Interspinous Process Spacing Device

ABSTRACT

Interspinous process spacing devices and associated methods are provided. In one embodiment, an interspinous process spacing device includes a first attachment side, a second attachment side, and a spacer. The first attachment side and the second attachment side each include a central portion, a first wing portion, and a second wing portion. The central portion includes an inner surface extending along at least a majority of an anterior-posterior height of the central portion, and the first wing portion includes an inner surface extending along at least a majority of an anterior-posterior height of the first wing portion. The inner surface of the first wing portion extends in a direction transverse to the inner surface of the central portion, and the anterior-posterior height of the first wing portion is less than the anterior-posterior height of the central portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/036,329, filed Jul. 16, 2018, which is a continuation of U.S. patentapplication Ser. No. 15/339,216, filed Oct. 31, 2016, now U.S. Pat. No.10,022,162, which is a continuation of U.S. patent application Ser. No.14/069,832, filed Nov. 1, 2013, now U.S. Pat. No. 9,561,061, which is acontinuation of U.S. patent application Ser. No. 13/047,472, filed Mar.14, 2011, now U.S. Pat. No. 8,591,547, issued Nov. 26, 2013, whichclaims priority to U.S. Provisional Patent Application Ser. No.61/313,169 filed on Mar. 12, 2010, the entire contents of which arehereby incorporated by reference.

FIELD OF THE INVENTION

The invention relates generally to devices for use during spinalsurgery, and methods pertaining thereto, and more particularly todevices and methods for providing spacing between adjacent spinousprocesses.

BACKGROUND OF THE INVENTION

Spinal discs and/or other vertebral changes can cause spinal diseasethat often leads to patient discomfort or even paralysis. For example,intervertebral spinal discs, which lie between adjacent vertebrae, canbreak down or degenerate, resulting in disc fluid loss and consequentlyresulting in a loss of disc flexibility. In addition, discs can becomethinner, allowing the vertebrae to move closer together, may tear orcrack in the outer layer and/or the annulus of the disc, and/or bulgeoutwardly. Facet joint degeneration may also lead to spinal disease.Physical trauma (e.g., accidents, injuries, strains, etc.) may causespinal column changes, and spinal stenosis can cause the spinal canal tonarrow due to excessive bone growth and/or thickening of tissue. In allof these conditions, the spinal canal through which the spinal cord andthe spinal nerve roots pass may become narrowed, creating pressure onnerve tissue. Such pressure can cause pain, numbness, weakness, or evenparalysis in various parts of the body.

Some methods for treating spinal diseases, such as those describedabove, limit the movement of adjacent vertebrae relative to one anotherto limit the additional pressure on the local nerve tissue bymaintaining a minimum disc space and/or space surrounding the adjacentvertebrae. Various methods have been performed to maintain this minimumspace, including disc implants and spinal fusions. One method includesimplanting a spacer between two adjacent posteriorly extending spinousprocesses, which in effect maintains a maximum space between thecorresponding vertebrae. Some existing spacer implant devices areimplanted by affixing the device to adjacent spinous processes. Existingspacer implants, however, do not provide complete access to insert bonegrowth promoting substances into the spacer after implant. In addition,existing spacer implants do not provide structural integrity between twoadjacently implanted spacers. Moreover, the procedures required toimplant existing spacer implant devices are overly complicated,requiring the use of multiple tools to position, tighten, and secure theimplants to the spinous processes.

Therefore, there remains a need for improved interspinous process spacerimplants.

SUMMARY OF THE INVENTION

Various embodiments described herein provide devices and associatedmethods for treating spinal disease. According to one embodiment, aninterspinous process spacing device is provided. The device includes afirst attachment side and a second attachment side, whereby eachattachment side includes one or more slots formed in the outer surfaceand oriented proximate one end for receiving fasteners extendinginwardly from a second interspinous process spacing device. The devicefurther includes a spacer tray positioned between the first attachmentside and the second attachment side, the spacer tray extending in asubstantially perpendicular orientation from the first attachment sideand slideably insertable through a tray slot formed in the secondattachment side, wherein the spacer tray is adapted to retain adjacentspinous processes in a spaced apart orientation. The device furtherincludes securing means for securing the second attachment side relativeto the first attachment side, wherein, upon securing the secondattachment side relative to the first attachment side by the securingmeans, the interspinous process spacing device is engaged with theadjacent spinous processes.

In one aspect, the spacer tray comprises an arcuate cross-sectionalshape and is substantially open and accessible from the posteriordirection. The spacer tray is adapted to retain bone growth promotingsubstance and to maximize the open space above the spacer tray andbetween the spinous processes, wherein the bone growth promotingsubstance is packable after engaging the first attachment side and thesecond attachment side to adjacent spinous processes. In anotherembodiment, the spacer tray comprises two separate members forming aspace therebetween.

According to one aspect, the securing means can include at least one of:(a) at least one worm drive assembly; (b) at least one rack and pinionassembly; (c) at least one screw extending between and operablyconnecting the first attachment side and the second attachment side; (d)a geared rack and ratchet assembly; or (e) at least one set screwassembly.

In one aspect, there are at least two spaced apart securing mechanismsextending between and operably connecting the first attachment side andthe second attachment side, wherein each of the at least two spacedapart securing mechanisms can be independently and incrementallyactuated causing each end of the attachment sides to engage therespective spinous process independently.

According to one aspect, the interspinous process spacing device is afirst interspinous process spacing device, and a second interspinousprocess spacing device is included. The second interspinous processspacing device includes a first bent attachment side and a second bentattachment side, wherein each bent attachment side comprises asubstantially flat end and an offset end adapted to overlap an adjacentportion of the respective attachment sides of the first interspinousprocess spacing device.

According to one aspect including a second interspinous process spacingdevice, each of the first attachment side and the second attachment sideof the second interspinous process spacing device has one or moreintegration means for integrating and attaching the offset end of thesecond interspinous process spacing device with a portion of therespective attachment side of the first interspinous process spacingdevice.

According to various aspects, the first interspinous process spacingdevice may be implantable inferior or superior to the secondinterspinous process spacing device.

In a different embodiment, an interspinous process spacing system isprovided. The interspinous process spacing system includes a firstinterspinous process spacing device and a second interspinous processspacing device. The interspinous process spacing device comprises twosubstantially flat attachment sides and a first spacer tray positionedtherebetween, wherein one of the two substantially flat attachment sidesis slideably positionable over the spacer tray. The second interspinousprocess spacing device comprises two bent attachment sides and a secondspacer tray positioned therebetween, wherein each of the bent attachmentsides comprises a substantially flat end and an offset end. Afterimplantation of the first interspinous process spacing device on a firstand a second adjacent spinous process, the offset ends of the two bentattachment sides of the second interspinous process spacing device atleast partially overlap respective adjacent ends of the substantiallyflat attachment sides of the first interspinous process spacing devicewhen implanting the second interspinous process spacing device on thesecond and a third spinous process adjacent to the second spinousprocess.

According to yet another embodiment, an interspinous process spacingdevice kit is provided. The interspinous process spacing device kit mayinclude: a first interspinous process spacing device comprising a firstattachment side and a second attachment side, the first and the secondattachment sides of the first interspinous process spacing device havinga substantially flat configuration; at least one additional interspinousprocess spacing device comprising a first attachment side and a secondattachment side, the first and the second attachment sides of the atleast one additional interspinous process spacing device having a bentconfiguration adapted to overlap a portion of a respective attachmentside of the first interspinous process spacing device; and at least oneinsertion instrument adapted for retaining at least one of the firstinterspinous processing spacing devices or the at least one additionalinterspinous process spacing device and implanting the same.

The kit may include a first insertion instrument and a second insertioninstrument, wherein the first insertion instrument is adapted forimplanting at least one of the first interspinous process spacingdevices or the at least one additional interspinous process spacingdevice in a first orientation, and the second insertion instrument isadapted for implanting at least one of the first interspinous processingspacing devices or the at least one additional interspinous processspacing device in a second orientation. Each insertion instrument mayinclude a first arm and a second arm, wherein the second arm isremovably and pivotally attachable to the first arm.

According to yet another embodiment, a method for implanting aninterspinous process spacing device is provided.

According to yet another embodiment, a method for treating a spinaldisorder including implanting one or more interspinous process spacingdevices is provided.

According to yet another embodiment, a method for manufacturing aninterspinous process spacing device is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will be betterunderstood and more readily apparent when considered in conjunction withthe following detailed description and accompanying drawings whichillustrate, by way of example, embodiments of interspinous processspacing devices, and in which:

FIG. 1 is a profile view of three interspinous process spacing devices,according to an example embodiment.

FIG. 2A is an isometric view of a second attachment side of aninterspinous process spacing device, according to an example base plateembodiment. FIG. 2B is a top view of a second attachment side of aninterspinous process spacing device, according to an example embodiment.FIG. 2C is a back view of a second attachment side of an interspinousprocess spacing device, according to an example embodiment. FIG. 2D is aside view of a second attachment side of an interspinous process spacingdevice, according to an example embodiment. FIG. 2E is a top view afirst attachment side of an interspinous process spacing device,according to an example embodiment. FIG. 2F is an isometric view of afirst attachment side of an interspinous process spacing device,according to an example embodiment. FIG. 2G is a side view of a firstattachment side of an interspinous process spacing device, according toan example embodiment. FIG. 2H is a back view of a first attachment sideof an interspinous process spacing device, according to an exampleembodiment.

FIG. 3A is an isometric view of a second attachment side of aninterspinous process spacing device, according to an example linkerplate embodiment. FIG. 3B is a top view of a second attachment side ofan interspinous process spacing device, according to an exampleembodiment. FIG. 3C is a back view of a second attachment side of aninterspinous process spacing device, according to an example embodiment.FIG. 3D is a side view of a second attachment side of an interspinousprocess spacing device, according to an example embodiment. FIG. 3E is atop view a first attachment side of an interspinous process spacingdevice, according to an example embodiment. FIG. 3F is an isometric viewof a first attachment side of an interspinous process spacing device,according to an example embodiment. FIG. 3G is a side view of a firstattachment side of an interspinous process spacing device, according toan example embodiment. FIG. 3H is a back view of a first attachment sideof an interspinous process spacing device, according to an exampleembodiment.

FIGS. 4A-4E are views of securing means integrated with interspinousprocess spacing devices, according to example base plate and overlappinglink plate embodiments. FIG. 4A is a top view of two interlinkedinterspinous process spacing devices. FIG. 4B is a top view of onesecured interspinous process spacing base device and one unsecuredinterspinous process spacing link device. FIG. 4C is an isometeric viewof one secured interspinous process spacing base device and oneunsecured interspinous process spacing link device. FIG. 4D is a back(outside) view of a first attachment side of an interspinous processspacing device having a base plate fastened to a link plate device. FIG.4E is a back view of a second attachment side of an interspinous processspacing device having a base plate fastened to a link plate device.

FIG. 5A is a back view of a first attachment side of an interspinousprocess spacing device having a base plate fastened to a link platedevice showing maximum rotational range when connected to a firstaperture, according to an example embodiment. FIG. 5B is a back view ofa first attachment side of an interspinous process spacing device havinga base plate fastened to a link plate device showing maximum rotationalrange when connected to a second aperture, according to an exampleembodiment. FIG. 5C is a back view of a first attachment side of aninterspinous process spacing device having a base plate with multipleoverlapping apertures in an inch-worm formation, for receiving afastener of another link plate device, according to an exampleembodiment.

FIG. 6A is an isometric view of a set of a base plate interspinousprocess spacing devices having a gradient of spacer tray widths,according to an example embodiment. FIG. 6B is an isometric view of aset of link plate interspinous process spacing devices having a gradientof spacer tray widths, according to an example embodiment.

FIG. 7A is a side view of a L5-S1 sacrum interspinous process spacingbase device, according to an example embodiment. FIG. 7B is an isometricview of a L5-S1 sacrum interspinous process spacing base device,according to an example embodiment. FIG. 7C is an isometric view of afirst attachment side of an L5-S1 sacrum interspinous process spacingbase device, according to an example embodiment. FIG. 7D is an isometricview of an alternative L5-S1 sacrum interspinous process spacing linkdevice, according to an example embodiment. FIG. 7E is an isometric viewof a second attachment side of a L5-S1 sacrum interspinous processspacing link device, according to an example embodiment.

FIG. 8A is an isometric view of an interspinous process spacing device,according to an example embodiment. FIG. 8B is an exploded isometricview of an interspinous process spacing device, according to an exampleembodiment. FIG. 8C is an exploded isometric view of an interspinousprocess spacing device, according to an example embodiment. FIG. 8D is aside view of an interspinous process spacing device, according to anexample embodiment.

FIG. 9A is an isometric view of a first attachment side of aninterspinous process spacing device link plate with an alternativespacer tray, according to an example embodiment. FIG. 9B is an explodedisometric view of a first attachment side of an interspinous processspacing device link plate with an alternative spacer tray, according toan example embodiment. FIG. 9C is an exploded isometric view of a firstattachment side of an interspinous process spacing device link platewith an alternative spacer tray, according to an example embodiment.FIG. 9D is an isometric view of a first attachment side of aninterspinous process spacing device link plate with an alternativespacer tray, according to an example embodiment.

FIG. 10 is an isometric view of an alternative interspinous processspacing device, according to an example embodiment.

FIG. 11A is an isometric view of an alternative interspinous processspacing device, according to an example embodiment. FIG. 11B is anisometric view of the first attachment side of the alternativeinterspinous process spacing device integrating an alternative worm-gearadvancement mechanism for the first and second attachment sides,according to an example embodiment. FIG. 11C is an isometric view of thealternative interspinous process spacing device, according to an exampleembodiment. FIG. 11D is an isometric view of the alternativeinterspinous process spacing device implanted onto a spine, according toan example embodiment.

FIG. 12A is an isometric outside view of the first attachment side ofthe alternative interspinous process spacing device, according to anexample embodiment. FIG. 12B is an isometric inside view of the firstattachment side of the alternative interspinous process spacing device,according to an example embodiment. FIG. 12C is an isometric view of afloating receiving member of the alternative interspinous processspacing device, according to an example embodiment. FIG. 12D is anisometric view of a floating receiving member of the alternativeinterspinous process spacing device, according to an example embodiment.FIG. 12E is an isometric view of a floating receiving member of thealternative interspinous process spacing device, according to an exampleembodiment. FIG. 12F is a side view of a floating receiving member ofthe alternative interspinous process spacing device, according to anexample embodiment. FIG. 12G is an isometric view of the interface of afloating receiving member integrating with the first attachment side ofthe alternative interspinous process spacing device, according to anexample embodiment. FIG. 12H is an inner isometric view of the interfaceof a floating receiving member integrating with the first attachmentside of the alternative interspinous process spacing device, accordingto an example embodiment. FIG. 12I is an outside rear view of theinterface of a floating receiving member integrating with the firstattachment side of the alternative interspinous process spacing device,according to an example embodiment. FIG. 12J is an isometric view of analternative interspinous process spacing device, according to an exampleembodiment. FIG. 12K is an isometric view of an alternative interspinousprocess spacing device integrating an alternative advancement mechanismfor the first and second attachment sides, according to an exampleembodiment. FIG. 12L is an isometric view of an alternative interspinousprocess spacing device integrating an alternative advancement mechanismfor the first and second attachment sides, according to an exampleembodiment.

FIG. 13A is an isometric view of a top down or universal surgicalinstrument for implanting and compressing/advancing two attachment sidesof an interspinous process spacing device, according to an exampleembodiment. FIG. 13B is a side view of a universal surgical instrumentfor implanting and compressing/advancing two attachment sides of aninterspinous process spacing device, according to an example embodiment.FIG. 13C is a side view of a universal surgical instrument forimplanting and compressing/advancing two attachment sides of aninterspinous process spacing device, according to an example embodiment.FIG. 13D is a detailed side view of a universal surgical instrument forimplanting and compressing/advancing two attachment sides of aninterspinous process spacing device, according to an example embodiment.

FIG. 14A is a side view of a first arm of a top down or universalsurgical instrument for implanting and compressing/advancing twoattachment sides of an interspinous process spacing device, according toan example embodiment. FIG. 14B is an alternative side view of a firstarm of the example embodiment. FIG. 14C is an alternative side view of afirst arm of the example embodiment. FIG. 14D is a side view of a secondarm of the example embodiment. FIG. 14E is an alternative side view of asecond arm of the example embodiment. FIG. 14F is an alternative sideview of a second arm of the example embodiment.

FIG. 15A is a side view of a separate first and second arm of a top downor universal surgical instrument for implanting andcompressing/advancing two attachment sides of an interspinous processspacing device, according to an example embodiment. FIG. 15B is a sideview of a further advanced (almost engaged) first and second arm of atop down surgical instrument for implanting and compressing/advancingtwo attachment sides of an interspinous process spacing device,according to an example embodiment.

FIG. 16A is a side view of a top down or universal surgical instrumentfor implanting and compressing/advancing two attachment sides of aninterspinous process spacing device showing an unengaged mechanicalactuation means, according to an example embodiment. FIG. 16B is a sideview of a top down surgical instrument for implanting andcompressing/advancing two attachment sides of an interspinous processspacing device showing an engaged mechanical actuation means, accordingto an example embodiment. FIG. 16C is an isometeric view of a top downsurgical instrument for implanting and compressing/advancing twoattachment sides of an interspinous process spacing device showing themechanical actuation means, according to an example embodiment.

FIG. 17A is a side view of a second inserter arm of a surgicalinstrument for implanting an interspinous process spacing device,according to an example embodiment. FIG. 17B is an alternative side viewof the second inserter arm of the example embodiment. FIG. 17C is analternative side view of the second inserter arm of the exampleembodiment. FIG. 17D is a side view of the first arm of the exampleembodiment. FIG. 17E is an alternative side view of a first arm of theexample embodiment. FIG. 17F is an alternative side view of a first armof the example embodiment.

FIG. 18A is an isometric view of a first and second inserter arm of asurgical instrument for implanting an interspinous process spacingdevice, according to an example embodiment. FIG. 18B is a view of theretained first and second inserter arms of the example embodiment. FIG.18C is a side view of the retained first and second inserter arms of theexample embodiment.

FIG. 19A is an isometric view of a compressor tool positioning first andsecond inserter arms of a surgical instrument for implanting aninterspinous process spacing device, according to an example embodiment.FIG. 19B is an isometric view of a compressor tool positioning first andsecond inserter arms of a surgical instrument for implanting aninterspinous process spacing device, according to an example embodiment.

FIG. 20A is a side view of a compressor tool for implanting aninterspinous process spacing device, according to an example embodiment.FIG. 20B is an isometric view of a compressor tool for implanting aninterspinous process spacing device, according to an example embodiment.FIG. 20C is an alternative side view of a compressor tool for implantingan interspinous process spacing device, according to an exampleembodiment.

FIG. 21A is a side view of an interspinous process space measurementinstrument, according to an example embodiment. FIG. 21B is an isometricview of an interspinous process space measurement instrument, accordingto an example embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As required, detailed embodiments of the invention are disclosed herein.However, it is to be understood that the disclosed embodiments aremerely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the invention in virtually any appropriatelydetailed structure.

Embodiments of the invention provide interspinous process spacingdevices and methods for their use and manufacture. As described above,an interspinous process spacing device provides a spacer insertedbetween posteriorly extending spinous processes of adjacent vertebrae tomaintain minimum spacing between the spinous processes. Accordingly, asingle interspinous process spacing device is designed to limit movementof only two adjacent vertebrae. According to certain embodimentsdescribed herein, an interspinous process spacing system is providedwith at least two individual interspinous process spacing devicesimplantable in an integrated, overlapping configuration. This integratedand overlapping configuration improves the stability of the adjacentvertebrae since the two attachment sides are engaged with each other,thus increasing the surface area of each individual attachment side thatcan engage the surface of the respective spinous process, since the twoattachment sides do not have to attach adjacent to each other, butoverlapping such that one is attached to the top of the other. Theinvention provides that a single interspinous process spacing device oftwo attachment sides, also referred to as a pair of base plates, can beimplanted alone having an integration mechanism, such as aperturestherein, for future implantation of an overlapping second interspinousprocess spacing device of two attachment sides, also referred to as apair of link plates.

According to one embodiment, a first interspinous process spacing deviceis implantable on two adjacent vertebrae by affixing to the spinousprocess of each vertebrae. A second interspinous process spacing deviceis implantable on the next adjacent vertebrae (e.g., in the superior orinferior direction) by affixing to the spinous process of the adjacentvertebrae and affixing to the adjacent end of the first interspinousprocess spacing device already implanted. According to one embodiment,to achieve this integrated configuration, the second (and succeeding)interspinous process spacing device has attachment sides in a bentconfiguration to overlap the attachment sides of the first interspinousprocess spacing device. The interspinous process spacing devices caninclude an integration mechanism, such as, but not limited to, a balland socket arrangement or a pin and hole (aperture or slot) arrangement,or a pin and overlapping holes arrangement, or a hinge arrangement, or abone engaging spike and hole arrangement for securely overlappingattachment sides of a first and second interspinous process spacingdevice and, in the case of a spiked integration mechanism, furtherengaging the spinous process. In various embodiments, the integrationmechanism may allow for overlapping attachment sides of first and secondinterspinous process spacing devices without requiring a bentconfiguration of the attachment sides, as further described below.

Each of the interspinous process spacing devices includes a firstattachment side and a second attachment side in an approximatelyparallel orientation relative to each other. Each of the attachmentsides aligns and selectively engages a respective side of two adjacentspinous processes to retain the implant in position. Thus, theattachment sides are adjustable in a substantially perpendiculardirection relative to their orientation (e.g., along the axis of thespacer tray extending between them) to permit closing and tighteningthem on the spinous process sandwiched therebetween. In one embodiment,the inner surfaces of each of the attachment sides include multiplefasteners (e.g., teeth, barbs, hooks, spikes, or any other grippingsurface or other suitable attachment means) protruding therefrom, whichinterface with the surfaces of the spinous processes to facilitateattaching the attachment sides thereto. In one example, the fastenerscan be positioned at or near the edges and/or corners of each attachmentside to align with the spinous processes during implantation.

In one embodiment in which multiple interspinous process spacing devicesare intended to be used to fasten to more than two adjacent vertebrae,the attachment sides of the first interspinous process spacing devicehave a substantially flat configuration, whereas the attachment sides ofthe second (and any subsequent) interspinous process spacing device areformed in a bent configuration, such that a portion of each attachmentside is offset from the remaining portion of the attachment side topermit overlapping the first interspinous process spacing device duringimplantation. As such, the offset portion is set out a distanceapproximately equal to, or slightly larger or smaller than, thethickness of the attachment side. To improve securing the secondinterspinous process spacing device to the first, the outer surfaces ofthe attachment sides of the first interspinous process spacing devicemay include apertures (e.g., holes, slots, etc.) oriented to receivefasteners extending from the inner surfaces of the offset portion of theattachment sides of the second interspinous process spacing device wherethe two overlap. Inserting some of the fasteners of the secondinterspinous process spacing device into the first device increases thepurchase and stability of the two devices together, improving theeffectiveness of the implant. In other embodiments, however, other meansfor allowing an overlapping arrangement of multiple interspinous processspacing devices can be used.

In addition, according to various embodiments described herein, theinterspinous process spacing devices include an improved spacer trayconfigured to permit increased access and provide an increased area forbone growth above the spacer tray and between the spinous processesafter implant. Access to the tray space and maximized open space betweenthe spinous processes after implant is beneficial when providing a bonegrowth promoting substance to fuse the spinous processes above thespacer tray. The amount and orientation of the bone material can havedirect consequences on its ability to promote bone and other tissuein-growth, further strengthening the implant and its fixation to thevertebrae. By orienting the spacer tray such that it will be positionedproximate the vertebrae when implanted, bone and other tissue in-growthis improved by increasing the surface area, and the amount and proximityof the bone growth promoting substance to the vertebrae and othertissue. The spacer tray can vary in length, width and in rotatableposition about an axis defined by its length.

As described, at least one attachment side of each interspinous processspacing device is configured to slide along the spacer tray to allowclosing the attachment sides on the adjacent spinous processes. Eachinterspinous process spacing device further includes securing means tosecure the attachment sides in position upon engaging the spinousprocesses. The securing means may vary according to differentembodiments, which include, but are not limited to, worm drivemechanisms, gear and pinion mechanisms, ratchet and gear mechanisms(like a lock tie or cable tie), cam mechanisms, one or two spaced apartscrews connecting the two attachment sides, any variation of theaforementioned mechanisms with only a single or multiplescrew/gear/ratchet mechanisms, etc., one or more set screws, a separateclamping means combined with a set screw, or any combination thereof.

Embodiments that have at least two spaced apart securing mechanismsallow tightening each side of the interspinous process spacing deviceindependently. As such, the attachment sides can be tightened using a“walking” approach by alternating between incremental actuations of eachmechanism. Tightening each side of the interspinous process spacingdevice independently allows the attachment sides to close on theadjacent spinous processes in a more tight and secure configurationirrespective of varied thicknesses or shapes of the spinous processes.Otherwise, without providing independent variability when tighteningeach end of the attachment sides, the interspinous process spacingdevice may not as securely engage adjacent spinous processes havingvaried thicknesses. Moreover, the two spaced apart securing mechanismsmay optionally avoid having to use a separate clamping and/or insertioninstrument to secure the interspinous process spacing device to thespinous processes, which is required by prior devices to achieve tightfixation. However, in some embodiments described below, one may opt touse an additional insertion instrument, which may be used to provide theinitial orientation and attachment or clamping of an interspinousprocess spacing device to the spinous processes, while the interspinousprocess spacing device and its integrated securing means may be used toachieve final fixation and secure engagement to the spinous processes.However, other securing mechanisms described herein that do not includetwo spaced apart mechanisms provide the additional advantages of asingle device for securing and the unique application of mechanicalsecuring components that tighten the two attachment sides, whichsimplifies the implantation procedure.

The present invention provides an interspinous process spacing device,comprising a first attachment side and a second attachment side, eachattachment side comprising one or more slots formed therein and orientedproximate one end for receiving fasteners extending inwardly from asecond interspinous process spacing device. The interspinous processspacing device further comprises a spacer tray positioned between thefirst attachment side and the second attachment side, the spacer trayextending from the first attachment side and slideably insertablethrough a spacer tray slot formed in the second attachment side, whereinthe spacer tray is adapted to retain adjacent spinous processes in aspaced apart orientation. The interspinous process spacing devicefurther comprises securing means for securing the second attachment siderelative to the first attachment side, wherein, upon securing the secondattachment side relative to the first attachment side by the securingmeans, the interspinous process spacing device is engaged with theadjacent spinous processes. In certain embodiments of the interspinousprocess spacing device, the one or more slots for receiving fastenersfrom a second interspinous process spacing device are oriented proximateeach end of the first attachment side and the second attachment side. Incertain embodiments of the interspinous process spacing device, the oneor more bone fasteners extend inwardly on one end of the firstattachment side and the second attachment side. In certain embodimentsof the interspinous process spacing device, the one or more bonefasteners extend inwardly on each end of the first attachment side andthe second attachment side.

In certain embodiments of the interspinous process spacing device, eachattachment side has a central portion and two wing portions extending inopposite directions from the central portion, and the one or more bonefasteners and the one or more slots for receiving extension fastenersfrom a second interspinous process spacing device are located on atleast one wing portion. In certain embodiments of the interspinousprocess spacing device, each wing portion has more than one slot forreceiving extension fasteners from a second interspinous process spacingdevice. In certain embodiments of the interspinous process spacingdevice, one wing portion of the first and second attachment sides hasone extension fastener extending inwardly for attaching to anotherinterspinous process spacing device.

In certain embodiments of the interspinous process spacing device, themeans for securing the second attachment side relative to the firstattachment side is a bearing screw extending posteriorly through acentral portion of second attachment side to the tray slot. In certainembodiments of the interspinous process spacing device, the tray slotengages the spacer tray with freedom of movement to permit at least 20degrees of lateral rotation of the second attachment side relative tothe first attachment side prior to engaging the securing means.

In certain embodiments of the interspinous process spacing device, thespacer tray comprises a T-shaped cross-section, and the tray slot in thesecond attachment side has a reciprocating T-shape. In certainembodiments of the interspinous process spacing device, the bottom ofthe T-shape is medially disposed from the first attachment side, and thecross-sectional shape tapers to a point on the spacer tray to facilitateinsertion of the tray through the ligament and angled insertion of thetray through the tray slot in the second attachment side.

In certain embodiments of the interspinous process spacing device, thespacer tray has an arcuate longitudinal shape, such that the spacer trayextends in a posterior curvature to facilitate angled insertion throughligaments and into the tray slot. In certain embodiments, at least theend portion of the spacer tray extends in an arcuate shape correspondingto the arc created when the sides are attached to a pivoting insertiontool and are drawn together, as described in more detail below. Incertain embodiments of the interspinous process spacing device, thespacer tray extends perpendicularly before the posterior curvature tofacilitate angled insertion through the tray slot.

In certain embodiments of the interspinous process spacing device, thespacer tray comprises an arcuate cross-sectional shape such that uponimplanting, the spacer tray is posteriorly open and accessible. Incertain embodiments of the interspinous process spacing device, thespacer tray is adapted to retain bone growth promoting substance,wherein the bone growth promoting substance is packable after engagingthe first attachment side and the second attachment side to adjacentspinous processes.

In certain embodiments of the interspinous process spacing device, thesecuring means for securing the second attachment side relative to thefirst attachment side is at least one set screw extending through thecentral portion from the posterior orientation to the tray slot tosecure the second attachment side to the spacer tray in a substantiallyfixed position. In various embodiments, the securing means comprises atleast one of: (a) at least one worm drive assembly; (b) at least onerack and pinion assembly; (c) at least one screw extending between andoperably connecting the first attachment side and the second attachmentside; (d) a geared rack and ratchet assembly; or (e) at least one setscrew assembly.

In certain embodiments of the interspinous process spacing device, thesecuring means comprises at least two spaced apart securing mechanismsextending between and operably connecting the first attachment side andthe second attachment side, wherein each of the at least two spacedapart securing mechanisms can be independently and incrementallyactuated causing each end of the attachment sides to engage therespective spinous process independently.

In certain embodiments of the interspinous process spacing device, thefirst and second attachment side each have an insertion instrumentreceptacle posteriorily located on each attachment side. In certainembodiments of the interspinous process spacing device, the size, shapeor indicia of the insertion instrument receptacle on the firstattachment side is different from the size, shape or indicia of theimplantation instrument receptacle on the second attachment side inorder to facilitate connection to the correctly corresponding ends ofthe insertion instrument.

In certain embodiments, the interspinous process spacing device is afirst interspinous process spacing device (or pair of base plates), andfurther comprising a second interspinous process spacing device (or pairof link plates) comprising a first offset attachment side and a secondoffset attachment side, wherein each offset attachment side comprises asubstantially flat end and an offset end adapted to overlap over anadjacent portion of respective attachment sides of the firstinterspinous process spacing device and having fasteners extendinginwardly therefrom receivable into the slots in each attachment side ofthe first interspinous process spacing device.

In certain embodiments of the interspinous process spacing device, thesubstantially flat end further comprises one or more bone fastenersextending inwardly and one or more slots formed therein for receivingfasteners extending inwardly from a third interspinous process spacingdevice. In certain embodiments of the interspinous process spacingdevice, the first attachment side and the second attachment side of thesecond interspinous process spacing device each have an integrationmeans for integrating and attaching the offset end of the secondinterspinous process spacing device with a portion of the respectiveattachment side of the first interspinous process spacing device.

In certain embodiments of the interspinous process spacing device, theintegration means comprise fasteners extending inwardly from the secondinterspinous process spacing device which pivotally engage the one ormore slots formed in each attachment side of the first interspinousprocess spacing device, such that the second interspinous processspacing device can pivot through a 155 degree angle with respect to thefirst interspinous process spacing device. In certain embodiments of theinterspinous process spacing device, the second interspinous processspacing device can pivot through a 120 degree angle with respect to thefirst interspinous process spacing device. In certain embodiments of theinterspinous process spacing device, the second interspinous processspacing device can pivot posteriorly and anteriorly throughsubstantially equal degrees with respect to the first interspinousprocess spacing device.

In certain embodiments of the interspinous process spacing device, theintegration means comprises at least one of: (a) one or more fastenersextending from the inner surfaces of the offset end and receivable bythe one or more apertures formed in the respective attachment side ofthe first interspinous process spacing device; (b) at least one pinextending from the inner surfaces of the offset end and receivable bythe one or more apertures formed in the respective attachment side ofthe first interspinous process spacing device; (c) a domed surfaceextending from the inner surface of the offset end and receivable by adome-shaped recess formed in the respective attachment side of the firstinterspinous process spacing device; (d) a textured surface formed onthe inner surface of the offset end and mateable to a textured surfaceformed on the outer surface of the respective attachment side of thefirst interspinous process spacing device; or (e) a textured domedsurface extending from the inner surface of the offset end andreceivable by a complementarily-shaped textured recess formed in therespective attachment side of the first interspinous process spacingdevice.

In certain embodiments of the interspinous process spacing device, theoffset ends of the second interspinous process spacing device are offsetby a distance approximately equal to the thickness of the respectiveattachment side of the first interspinous process spacing device. Incertain embodiments of the interspinous process spacing device, thefirst interspinous process spacing device is implantable at an inferiorposition relative to the second interspinous process spacing device. Incertain embodiments of the interspinous process spacing device, thefirst interspinous process spacing device is implantable at a superiorposition relative to the second interspinous process spacing device.

In certain embodiments, the interspinous process spacing device isconfigured for implantation at the L5-S1 vertebrae and comprising afirst angled attachment side and a second angled attachment side,wherein each angled attachment side comprises an angled end adapted toaccommodate a sacrum. In certain embodiments, the first and secondangled attachment sides are each selectively adjustable for optimizingthe angle to fit the particular patient's sacrum anatomy and thensecuring the selected angle. The ends opposite the angled sacrumattachment ends can have bone fasteners extending from the innersurfaces thereof and one or more apertures therethrough, allowing thedevice to serve as a base plate for receiving fasteners on a secondsuperiorly located spacing device. Alternatively, the ends opposite theangled sacrum attachment ends can be offset and each have a fastener(such as a bone fastening spike) extending from the inner surfacesthereof, allowing the device to serve as a link plate to be receivedwithin one or more apertures in a second superiorly located spacingdevice. Both embodiments permit rotational optimization of the relativeangle between the first and second spacing devices to fit the patient'sanatomy. In certain embodiments of the interspinous process spacingdevice, the angled end of each angled attachment side of theinterspinous process spacing device further comprises one or more angledfasteners extending from the inner surface at an angle other than ninetydegrees and adapted for engaging the sacrum.

In certain embodiments of the interspinous process spacing device, eachattachment side has a central portion and two wing portions extending inopposite directions from the central portion superiorly and inferiorly,and the inferior wings each have the angled end adapted to accommodate asacrum and have one or more bone fasteners extending inwardly therefrom,and the superior wings each have one or more slots formed therein forreceiving extension fasteners from a second interspinous process spacingdevice.

In certain embodiments of the interspinous process spacing device, thesuperior wings each have one or more bone fasteners extending inwardlytherefrom. In certain embodiments of the interspinous process spacingdevice, the superior wings each have an extension fastener extendinginwardly for attaching to another interspinous process spacing device.In certain embodiments of the interspinous process spacing device, thebone fasteners on the inferior wings each comprise a bone screw ormovable spike or an axially expandable spike to engage the bone disposedthrough the wing. In certain embodiments of the interspinous processspacing device, the bone fasteners on the inferior wings furthercomprise one or more stationary spikes extending inwardly therefrom atangle different than an angle at which the bone screw or movable spikeis disposed through the wing.

In certain embodiments of the interspinous process spacing device, thesuperior wings each have more than one slot formed therein for receivingfasteners extending inwardly from a second interspinous process spacingdevice. In certain embodiments of the interspinous process spacingdevice, the superior wings permit a fastened second interspinous processspacing device to pivot up to a 155 degree or a 60 degree angle withrespect to the interspinous process device for implantation on thesacrum at the L5-S1 vertebrae.

The present invention further provides an interspinous process spacingsystem, comprising a first interspinous process spacing device and asecond interspinous process spacing device, wherein the firstinterspinous process spacing device comprises two substantially flatattachment sides and a first spacer tray positioned therebetween,wherein one of the two substantially flat attachment sides is slideablypositionable over the spacer tray. In certain embodiments of theinterspinous process spacing device, wherein the second interspinousprocess spacing device comprises two offset attachment sides and asecond spacer tray positioned therebetween, each of the offsetattachment sides comprises a substantially flat end and an offset end.

The invention provides in certain embodiments that after implantation ofthe first interspinous process spacing device on a first and a secondadjacent spinous process, the offset ends of the two offset attachmentsides of the second interspinous process spacing device at leastpartially overlap respective adjacent ends of the substantially flatattachment sides of the first interspinous process spacing device whenimplanting the second interspinous process spacing device on the secondand a third spinous process adjacent to the second spinous process.

In certain embodiments of the interspinous process spacing device, eachof the offset ends of the two offset attachment sides comprises anintegration means for integrating and attaching the offset end of thesecond interspinous process spacing device with a portion of therespective attachment side of the first interspinous process spacingdevice when overlapping.

In certain embodiments of the interspinous process spacing device, theintegration means comprise fasteners extending inwardly from the secondinterspinous process spacing device which pivotally engage the one ormore slots formed in each attachment side of the first interspinousprocess spacing device, such that the second interspinous processspacing device can pivot through a 155 degree angle with respect to thefirst interspinous process spacing device.

In certain embodiments of the interspinous process spacing device, eachof the substantially flat attachment sides and the offset attachmentsides comprises one or more bone fasteners extending from the innersurface for engaging respective spinous processes when implanted. Incertain embodiments of the interspinous process spacing device, thesubstantially flat end on each of the offset attachment sides of thesecond interspinous process spacing device comprises one or more slotsformed in an outer surface for receiving one or more fasteners extendingfrom an inner surface of a respective offset attachment side of a thirdinterspinous process spacing device adapted to overlap the substantiallyflat ends of the second interspinous process spacing device.

In certain embodiments the invention provides an interspinous processspacing device kit comprising: a first interspinous process spacingdevice comprising a first attachment side and a second attachment side,the first and the second attachment sides of the first interspinousprocess spacing device having a substantially flat configuration; asecond interspinous process spacing device comprising a first attachmentside and a second attachment side, the first and the second attachmentsides of the second interspinous process spacing device having an offsetconfiguration adapted to overlap a portion of a respective attachmentside of the first interspinous process spacing device; and at least oneinsertion instrument adapted for retaining at least one of the firstinterspinous processing spacing devices or the at least one additionalinterspinous process spacing device and implanting the same.

In certain embodiments of the interspinous process spacing device, eachinterspinous process spacing device further comprises a spacer traypositioned between the first attachment side and the second attachmentside, the spacer tray having a width and length extending from the firstattachment side and slideably insertable through a tray slot formed inthe second attachment side, wherein the spacer tray is adapted to retainadjacent spinous processes in a spaced apart orientation, and whereinthe kit further comprises a plurality of alternatively sized first andsecond interspinous process spacing devices having different spacer traywidths.

The present invention further provides a surgical instrument system forimplanting an interspinous process spacing device, comprising a meansfor positioning a first arm and a second arm in alignment for securingthe interspinous process spacing device onto spinal processes. Incertain embodiments of the surgical instrument system for implanting aninterspinous process spacing device, the proximal and distal ends areoffset to provide an unobstructed view of the distal ends when holdingthe proximal ends. In certain embodiments, each arm permits an engagedattachment side of the interspinous process spacing device at least 5degrees, or at least 10 degrees, and up to 30 degrees, of rotation aboutan axis defined by the engagement element on the distal end of the arm.In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the engagement element comprisesan engagement projection which releaseably engages an instrumentreceptacle on the attachment side of the interspinous process spacingdevice, a mount for movably holding the engagement projection, and animplant guide extending distally past the engagement projection whichengages an outer surface of an engaged attachment side of theinterspinous process spacing device.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the engagement projection on thesecond arm provides access to a securing means on the second attachmentside of the interspinous process spacing device to secure the secondside to the first side. In certain embodiments, the engagementprojection is a threaded screw which engages a reciprocal threadedinstrument receptacle instrument on the attachment side of theinterspinous process spacing device. In certain embodiments, thethreaded screw on the second arm is cannulated to provide accesstherethrough to a securing means on the second attachment side of theinterspinous process spacing device to secure the second side to thefirst side while the second side is engaged to the second arm.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the size, shape or indicia ofthe insertion instrument receptacle on the first attachment side isdifferent from the size, shape or indicia of the insertion instrumentreceptacle on the second attachment side to facilitate connection to thecorrectly corresponding ends of the insertion instrument.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the proximal ends of the firstand second arms are releasably connectable at more than one selecteddistance. In certain embodiments of the surgical instrument system forimplanting an interspinous process spacing device, the central portionsof the first and second arms are releasably and rotatably connectable.

In certain embodiments, the present invention provides a top-downsurgical instrument system for implanting an interspinous processspacing device, comprising a first arm having a proximal end, anelongated central portion and distal end, wherein the distal end has aninterspinous process spacing device engagement element for posteriorlyengaging a first attachment side of the interspinous process spacingdevice having a spacer tray extending inwardly therefrom. Certainembodiments comprise a second arm having a proximal end, an elongatedcentral portion and distal end, wherein the distal end has aninterspinous process spacing device engagement element for posteriorlyengaging a second attachment side of the interspinous process spacingdevice having a spacer tray slot therein for receiving the spacer tray.In such embodiments, the second arm is removably and pivotallyattachable to the first arm about an axis for positioning the first armand the second arm in alignment for securing the interspinous processspacing device onto spinal processes.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the second arm further comprisesa pivot member or pin located on the central portion and the first armfurther comprises a pivot channel or slot with a proximally orientedopening and a distally oriented curved retaining edge, such when the pinis slideably engaged in the slot against the retaining edge the firstand second arms are removeably and pivotally attached to form a hinge,wherein the hinge permits positioning the first arm and the second armin alignment for securing the interspinous process spacing device ontospinal processes.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, when the first and second armseach have a respective first and second attachment side of theinterspinous process spacing device engaged thereto, and the first andsecond arms are attached at the hinge, drawing the proximal ends of thearms together will align and insert the spacer tray into the spacer trayslot of the first and second attachment sides of the interspinousprocess spacing device for securing the interspinous process spacingdevice onto spinal processes.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the first arm further comprisesa releasable locking mechanism for selectively securing the pin of thesecond arm into the slot of the first arm. In certain embodiments, thereleasable locking mechanism is a leaf spring on the central portion ofthe first arm in blocking communication with the slot, such that the pinon the second arm can deflect the leaf spring during insertion into theslot and remain therein when the leaf spring returns to blockingcommunication to maintain the pin against the retaining edge on thefirst arm, and wherein the leaf spring can be manually disengaged fromblocking communication with the slot to release the pin and separate thefirst and second arms.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the surgical instrumentcomprises means for mechanically actuating the insertion instrument toclose and open the first arm and the second arm for tightening thesecond attachment side relative to the first attachment side. In certainembodiments, the means for mechanically actuating is a ratchet barpivotally mounted to the proximal end of the second arm and selectivelyengageable to the proximal end of the first arm, wherein the ratchet barhas a plurality of teeth on the proximal surface thereof which engage acorresponding flange on the proximal end of the first arm.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the ratchet bar has one or moreindicators of predetermined length corresponding to space between themounted sides of the interspinous process spacing device. In certainembodiments, the ratchet bar further comprises a threaded track and anut riding thereon outside the proximal end of the first arm formechanically forcing the proximal ends of the arms together.

The present invention further provides a surgical instrument system forimplanting an interspinous process spacing device, comprising a firstarm having a proximal end, an elongated central portion and distal end,wherein the distal end has an interspinous process spacing deviceengagement element for posteriorly engaging a first attachment side ofthe interspinous process spacing device having a spacer tray extendinginwardly therefrom. Such an embodiment also comprises a second armhaving a proximal end, an elongated central portion and distal end,wherein the distal end has an interspinous process spacing deviceengagement element for posteriorly engaging a second attachment side ofthe interspinous process spacing device having a spacer tray slottherein for receiving the spacer tray. This embodiment can further beused with a compressor tool for positioning the first arm and the secondarm in alignment for securing the interspinous process spacing deviceonto spinal processes.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the compressor tool has aproximal handle end a central portion and a distal pair of opposingtangs moveable throughout a range between an open position and acompression position. In certain embodiments, the distal end of each armcomprises compressor tool guide channels and compression pointindentations therein for receiving the compressor tool tangs. Thecompression points permit delivery of substantially equal amounts ofpressure across each attachment side of the plate, allowing lessinvasive surgical implantation with a single compressor tool than wouldbe required with multiple compression points and multiple compressiontools. In certain embodiments, the tangs have distal compressor tipsextending inwardly for engagement within the corresponding guidechannels and compression point indentations on the arms, wherein thecompression tool can rotate about an axis defined by the compressor tipsso as to provide a user with a range of approach angles and approachfrom either side of the implantation tool and compress the arms tosecure the aligned interspinous process spacing device onto spinalprocesses.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the proximal end of one armfurther comprises a retaining latch disposable on the distal end of theother arm to retain the arms in position relative to each other and inalignment for securing the interspinous process spacing device ontospinal processes.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the surgical instrumentcomprises means for mechanically actuating the insertion instrument toclose and open the first arm and the second arm for tightening thesecond attachment side relative to the first attachment side. In certainembodiments, the means for mechanically actuating is a ratchet barpivotally mounted to the proximal end of the second arm and selectivelyengageable to the proximal end of the first arm, wherein the ratchet barhas a plurality of teeth on the proximal surface thereof which engage acorresponding flange on the proximal end of the first arm. In certainembodiments, the ratchet bar has one or more indicators of predeterminedlength corresponding to space between the mounted sides of theinterspinous process spacing device. In certain embodiments, the ratchetbar further comprises a threaded track and a nut riding thereon outsidethe proximal end of the first arm for mechanically forcing the proximalends of the arms together.

The present invention also provides a surgical instrument for selectingan interspinous process spacing device. In certain embodiments, theselection instrument comprises a first arm having a proximal end, anelongated central portion and distal end, wherein the distal end has afirst interspinous process spacing measurement wing extending therefromcomprising a first spinous process stop element and a perpendicular wingtemplate, and a second arm having a proximal end, an elongated centralportion and distal end, wherein the distal end has a second interspinousprocess spacing measurement wing extending therefrom comprising a secondspinous process stop element and a perpendicular wing template. Incertain embodiments of the surgical instrument, the first and secondarms are pivotally attached about an axis for positioning the first andsecond interspinous process spacing measurement wings to measure spacebetween adjacent spinal processes. The instrument also allows forselection of an adjacent base plate or link plate superior or inferiorto the existing implanted plate.

In certain embodiments of the surgical instrument, the measurementdevice can further comprise first and second wing templates adapted tooverlap respective first and second adjacent spinal processes todetermine space available on each spinous process for engaging aninterspinous process implant. In certain embodiments, the instrumentdetermines the space available for implantation of either a base platedevice or an overlapping link plate device. In certain embodiments, theinstrument can be adapted such that the proximal end of the first orsecond arm has a measuring element attached thereto with indicia toregister length to the proximal end of the other arm, wherein saidlength corresponds to space between adjacent spinal processes asmeasured by the first and second spinous process stop elements. Incertain embodiments of the surgical instrument, drawing the proximalends of the arms together separates the wings to measure space betweenadjacent spinal processes. In one embodiment, the first or second wingtemplate, or both, comprises a fastener template extending therefromadapted to engage with a slot on an attachment side of an interspinousprocess spacing device previously implanted to determine space andorientation available for overlapping engagement of a link plate onto abase plate.

Example embodiments of interspinous process spacing devices are furtherdescribed with reference to the FIGS. 1-12. Extending posteriorly fromeach vertebra are spinous processes. Laminae connect the spinousprocesses to respective transverse processes. Facet joints between theprocesses of adjacent vertebrae guide articulation of the vertebrae.Interspinous process spacing devices as described herein may beimplanted between adjacent spinous processes of any of the cervical,thoracic, and/or lumbar vertebrae.

As shown in FIG. 1 are three engaged interspinous process spacingdevices—a first base plate type interspinous process spacing device 130,a second link plate type interspinous process spacing device 132overlapping the superior end of the first interspinous process spacingdevice 130, and a third link plate type interspinous process spacingdevice 134 overlapping the inferior end of the first interspinousprocess spacing device 130. The first interspinous process spacingdevice 130 includes a first attachment side 140 and a second attachmentside 142, engaging either side of the adjacent spinous processes.Similarly, the second and third interspinous process spacing devices132, 134 include a first attachment side 144 and a second attachmentside 146. According to this embodiment, the attachment sides 144, 146 ofthe second interspinous process spacing device have an offsetconfiguration to permit overlap with the first interspinous processspacing device 130. Thus, each of the first and second attachment sides144, 146 of the second and third interspinous process spacing devices132, 134 has a substantially flat end 148 and an offset end 149, withthe offset being approximately the anticipated thickness of the first orsecond attachment side 140, 142 of the first interspinous processspacing device 130 (or a slight variation thereof), which is describedand illustrated in more detail with reference to FIGS. 2-4.

According to various embodiments, the size and dimension of the firstand the second attachment sides 140, 142, 144, 146 may vary according tothe intended use of the interspinous process spacing devices 130, 132which may vary based at least in part on the intended implant locationon the spine, the patient size, the treatment, and the like. Forexample, attachment sides may vary in length and/or height toaccommodate the varying sizes of spinous processes. Moreover, asdescribed below with reference to FIGS. 5A-5C and 7A-7E, attachment sidegeometry may be adapted for implanting at specific locations of a spinethat require different configurations, such as at the L5-S1 vertebrae.

Similarly, spacer tray dimensions, as described below, may also vary insize, such as to accommodate varying patient and/or implant locationanatomy. In one example, the spacer tray may have a substantiallysmaller width than is illustrated in FIG. 1, which may facilitateinsertion through the ligaments existing between the spinous processes.Kits including interspinous process spacing devices with a range ofspacer tray widths to select from are provided, such as shown in FIG.6A-6B. In certain embodiments, the spacer tray widths can be provided inincrements ranging from less than or 8 mm, 10 mm, 12 mm, 14 mm, 16 mm,to 18 mm, or more, such as shown in FIGS. 6A-6B. Example spacer traylengths can be 10 mm to 30 mm, or 23.4 mm. In another example, aninterspinous process spacing device may not include a spacer tray. Aspacer tray selection instrument is also provided and is described inmore detail below with reference to FIGS. 21A and 21B.

In certain example embodiments, the width of the wings on a base andlink plate, such as shown in FIGS. 2-3 can be 3 mm, the width of thecentral portion of the first attachment side can be 6 mm, and the widthof the central portion of the second attachment side can be 8.5 mm. Anexemplary height for the base plate and link plate attachment sides is18 mm.

In certain example embodiments, the length of the wings on either sideof the spacer tray can be 10.5 mm for a first interspinous processdevice base plate and 12.5 mm for a second interspinous process devicelink plate. Therefore, for an example device with a 8 mm spacer traywidth, the total plate length for a base plate would be 29 mm, and for alink plate would be 31 mm.

Each of the interspinous process spacing devices 130, 132 may include aspacer tray 150 extending between attachment sides 140, 142 and 144,146, respectively. The spacer tray 150 is configured with surfaces toabut the spinous processes to maintain the spaced apart relationship ofthe spinous processes. According to various embodiments, as illustratedin FIGS. 1-12, the spacer tray 150 may have a substantially openconfiguration that is accessible from the posterior direction, whichserves to maximize the surface area for bone growth promotingsubstances. Access from the posterior direction allows the surgeon toinsert the bone growth promoting substance (or any other material tofacilitate bone in-growth, structural support, and/or healing) afterimplanting the interspinous process spacing devices. Otherwise, withoutposterior access, the bone growth promoting substance must be insertedprior to implantation, which likely will not result in the mosteffective placement and/or quantity of bone growth promoting substance.In contrast to conventional interspinous spacers, which typically have acircular cross-section and occupy a substantial area between adjacentspinous processes, the spacer tray 150 described herein has a reducedcross-sectional profile and a tapered width on the leading front edge,which eases insertion between the ligaments occupying the space betweenadjacent spinous processes. The conventional devices often requiresignificant retraction and/or cutting of the ligaments to implant adevice because the larger, circular cross-section of the componentsexisting between the sides cannot easily be inserted between theligaments, increasing the difficulty, risk, and healing time of theimplant procedure.

Accordingly, the spacer tray 150 described herein can be insertedbetween the ligaments without cutting due to its reduced, tapered, orflattened profile compared to the larger, circular cross-sections ofother devices. However, in other embodiments, the spacer tray 150 may beconfigured in a variety of shapes and sizes to accommodate anatomicalvariation among patients and intended treatment and space correction,and to accommodate the positioning of a securing mechanism, as furtherdescribed below. The spacer tray 150 may further optionally includeapertures through the spacer tray 150, which act to facilitate bone andtissue in-growth by maximizing the available surface area from theadjacent spinous processes and cause further fusion thereof. These andother features and variations thereof are discussed in more detail withreference to the following FIGS. 2-12.

Moreover, according to another embodiment, the spacer tray 150 may havea minimized width to increase the ease of insertion and to occupy lessspace between adjacent spinous processes. In fact, in one embodiment aspacer tray may not be included at all, and alignment, connection, andstability between the two attachment sides 140, 142 may be accomplishedby way of the securing means, such as those described with reference toFIGS. 8 and 10. In this embodiment, the securing means may further serveto absorb impact from, and to limit movement of, one or more of theadjacent spinous processes, which otherwise would be achieved by aspacer tray.

FIGS. 2-7 show details of interspinous process spacing devices accordingto one embodiment, such as the first interspinous process spacing device130 (as illustrated in FIG. 1). FIGS. 6-9 show example spacer tray 150configurations, according to various example embodiments. The firstattachment side 140 includes a spacer tray 150 extending in asubstantially perpendicular direction from the first attachment side140. The spacer tray 150 shown is configured to have a substantiallyarcuate cross-sectional shape, permitting access to the tray afterimplanting the interspinous process spacing device 130. However, thespacer tray may have any cross-sectional shape, such as, but not limitedto, flat, angled, a partial square, a partial hexagon, a partialoctagon, a T-shape, a cross shape, and the like, such as, but notlimited to, those illustrated by example in FIGS. 1-12. The dimensionsof the spacer tray 150 can depend upon the desired level of movementand/or size of the desired space to be retained between the two adjacentspinous processes. The spacer tray 150 may further optionally includechambers formed through the tray, which may be oriented to provideadditional clearance of the spacer tray 150 from posteriorly facing bonesurfaces (e.g., spinous processes, facet joints, etc.). Accordingly, aspacer tray 150 acts to maintain a minimum distance between adjacentspinous processes to move the vertebrae apart and relieve pressure onnerve tissue and/or facet joints.

The cross-sectional shape of the spacer tray 150 can facilitateinsertion into the tray slot 210. For example, as shown in FIGS. 2-7,the T-shaped cross-section, with the bottom of the T extending mediallyor downward into the spine provides a supporting lift for the tip of thespacer tray off of the vertebrae and into the tray slot. Similarly, thetapering cross-section of the tip of the spacer tray into a roundedpoint facilitates insertion into the slot, as well as facilitatinginsertion through the ligaments existing between the spinous processes.Finally, the arcuate longitudinal cross-section facilitates insertionwhen both sides are engaged with an insertion tool and being drawntogether in an arc, as described below.

Moreover, the spacer tray 150 is shaped to permit access from theposterior direction, which increases the ease with which bone growthpromoting substance is placed above the spacer tray 150 and proximatethe vertebrae, while also increasing the available spinous processsurface area. In some embodiments, bone growth promoting substance canbe inserted in or near other areas of the interspinous process spacingdevice. Also as illustrated in FIGS. 9B-9D, the spacer tray 150 canoptionally include tray apertures 320 or other openings extendingthrough the spacer tray 150 to further facilitate tissue and/or bonein-growth. Any number of tray apertures 320 may be included in any size,shape, or configuration. As used herein, bone growth promoting substancemay include, but is not limited to, bone paste, bone chips, bone strips,structural bone grafts, platelet-derived growth factors, bone marrowaspirate, stem cells, bone growth proteins, bone growth peptides, boneattachment proteins, bone attachment peptides, hydroxylapatite, calciumphosphate, and/or other suitable bone growth promoting substances.

The second attachment side 142 includes a tray slot 210 having a similarshape as the spacer tray 150 to permit the spacer tray 150 to slidetherethrough. Accordingly, the second attachment side 142 is slideablyadjustable along the axis of the spacer tray 150 so the secondattachment side 142 can move toward the first attachment side 140 whentightening to allow the attachment sides 140, 142 to be positioned alongeither side of, and secured to, the spinous processes. It is appreciatedthat in other embodiments, the spacer tray may extend from the secondattachment side and slideably pass through the first attachment side,and that the orientation relative to the patient's spine may vary fromthat described and illustrated herein.

According to one embodiment, as is shown in more detail with referenceto FIG. 4 and FIG. 6 (a simplified perspective view of an interspinousprocess spacing device), the tray slot 210 is sized slightly larger thanthe cross-section area of the spacer tray 150 to provide loose fittingof the second attachment side 142 over the spacer tray 150, permittingat least slight angular movement of the second attachment side 142relative to the first attachment side 140, but providing enoughconstraint so as to retain the approximate orientation of the secondattachment side 142 relative to the spacer tray 150. As a result of thisslight angular variation allowed, opposite ends of the attachment sidescan be tightened independently and can adapt to adjacent spinousprocesses having varied thicknesses (e.g., permitting the attachmentsides to close tighter or narrower on one end relative to the other,such as if one spinous process is smaller or narrower than the other).The size of the tray slot 210 relative to the spacer tray 150 may varyaccording to the desired level of angular variation of the secondattachment side 142 relative to the first attachment side 140. In otherembodiments, however, the tray slot 210 may form a tight fit around thespacer tray 150 to prevent significant angular variation or othermovement of the second attachment side 142 relative to the spacer tray150. The fit between the tray slot 210 and the spacer tray 150 furtherserves to absorb torque or any other force applied by the spacer tray150 against the second attachment side 142, providing increasedstability of the attachment sides 140, 142 relative to each other andagainst the patient's spinous processes when implanted.

In certain embodiments of the interspinous process spacing device, thetray slot engages the spacer tray with freedom of movement to permit atleast 20 degrees of lateral rotation of the second attachment siderelative to the first attachment side prior to engaging the securingmeans. However, in other embodiments, the tray slot 210 may form a moresecure fit with the spacer tray 150, preventing significant angularmovement therein. For example, in embodiments in which the securingmechanism utilizes a gearing mechanism, a tighter fit may serve toprevent cross-threading or poor meshing of the gearing mechanisms.

Also illustrated in FIGS. 2-7 are fasteners 220 extending from the innersurfaces of each of the attachment sides 140, 142. The fasteners 220improve the ability of the attachment sides 140, 142 to engage thespinous processes and/or serve as an integration means to engage theexterior surface of the adjacent interspinous process spacing device,such as is illustrated in and described with reference to FIGS. 5A-5C.In certain embodiments of the interspinous process spacing device, theintegration means comprise fasteners extending inwardly from the secondinterspinous process spacing device which pivotally engage the one ormore slots formed in each attachment side of the first interspinousprocess spacing device, such that the second interspinous processspacing device can pivot through a 155 degree angle with respect to thefirst interspinous process spacing device. In certain embodiments of theinterspinous process spacing device, the second interspinous processspacing device can pivot through a 60 degree angle with respect to thefirst interspinous process spacing device. In certain embodiments of theinterspinous process spacing device, such as illustrated in FIGS. 5A-5B,where multiple apertures are provided for the fastener, and wheremultiple apertures partially overlap as illustrated in FIG. 5C, thesecond interspinous process spacing device can pivot through a range ofangles with respect to the first interspinous process spacing device. Itis understood that the device can be configured for pivotal rotation ofthe first interspinous process spacing device relative to the secondinterspinous process spacing device through any range of degrees desiredincluding for example 180, 170, 160, 155, 150, 140, 130, 120, 110, 100,90, 80, 70, 60, 50, 40, 30, 20, 10, 5 and 0 degrees. In certainembodiments of the interspinous process spacing device, the secondinterspinous process spacing device can pivot posteriorly and anteriorlythrough substantially equal or unequal degrees in each direction withrespect to the first interspinous process spacing device.

The fasteners 220 illustrated in FIGS. 2-7 are shown as teeth or barbs,but any other fastening or other securing mechanism may be used,including, but not limited to, pins, hooks, wires, spikes, straps,clamps, sutures, adhesives, or any other suitable fastening mechanism.Moreover, according to various embodiments, the fasteners 220 may beinterchangeable with other types of fastening mechanisms and/or may beadjustable to accommodate varying anatomy among patients. In additionto, or in lieu of, the fasteners 220 shown in FIGS. 2-7, otherintegration means may be provided that facilitate the integration of andsecurement between two adjacent interspinous process spacing deviceswhen implanted in an overlapping configuration.

In the embodiments shown in FIGS. 1-7, the fasteners 220 are projectinginward from second link plates 144,146 of the second interspinousprocess spacing device toward slots 315 in base plates 140,142 of thefirst interspinous process spacing device to pivotally engage the twodevices together prior to further securing with securing means 230 whichis in this embodiment a set or bearing screw. Bone fastening members 225are shown on the inner surfaces of the plates. In certain embodiments,the bone fastening members alternately extend from each opposing plateto different points on the spinous process to minimize the potential forfracture by bearing directly on opposing sides of the bone. Examples ofthese and other integration members are illustrated in and describedwith reference to FIGS. 1-12.

Example securing means 230 are particularly illustrated by FIG. 4 withset screw extending through the central portion of the second attachmentside 142 onto the spacer tray 150 in the tray slot 210. Variousadditional example embodiments illustrated and described in more detailwith reference to FIG. 8. The securing means 230 illustrated in FIG. 8includes two spaced apart screws 310 extending between the attachmentsides 140, 142 and oriented substantially along the same axis as thespacer tray 150. In the embodiment illustrated in FIG. 8, the screws 310extend through the second attachment side 142 through apertures 312 andare received by the complementary threaded collars 314 extending fromthe inner surface of the first attachment side 140. However, it isappreciated that the screws 310 may instead pass through the firstattachment side 140 and be received by collars on the second attachmentside 142 in other embodiments. According to one embodiment, the threadedcollars 314 extend a given distance from the inner surface of the firstattachment side 140 so as to permit receiving the respective screws 310while the attachment sides 140, 142 are still sufficiently separated,and to reduce the length of the screws 310. The distance the threadedcollars 314 extend may vary, but can be determined to extend the maximumdistance without interfering with the vertebrae, other components of theinterspinous process spacing device, and/or access to spacer tray 150 toprovide bone growth promoting substance therein. Similarly, theorientation of the securing means 230 is chosen to avoid interferingwith the vertebrae (e.g., the spinous process) during implantation,while also providing maximum securing and purchase strength of theattachment sides 140, 142 to the spinous process. In another example,one or more screws 310 can be positioned between the space of a spacertray 150 formed from multiple members and creating a space therein.

Spaced apart screws (or other securing means, as described in moredetail below) permit independently adjusting opposite ends of theattachment sides 140, 142 and thus independently securing opposite endsof the attachment sides 140, 142 to the respective spinous process. Forexample, during tightening, the superior screw can be incrementallytightened, then the inferior screw can be incrementally tightened, andso forth until each end of the attachment sides 140, 142 is secured tothe respective spinous process. This method allows tightening theinterspinous process spacing device by “walking” opposite ends, and thusaccounting for varied thicknesses of adjacent spinous processes.Additional embodiments including spaced apart screws or similar spacedapart securing means are described with reference to FIGS. 8A-8D.

Moreover, some example securing means described herein may generallyavoid having to use a separate clamping and/or insertion instrument. Bytightening the screws 310, the attachment sides 140, 142 close on thespinous processes without any additional clamping or tightening force.However, other securing means described herein can be implanted using aninsertion instrument to facilitate retaining desired positioning of theinterspinous process spacing device and/or to tighten the attachmentsides 140, 142 against the spinous processes. In certain embodiments,the insertion instrument can also aid in aligning and engaging the twoattachment sides of the device without requiring removal of the spinousprocess ligament. For example, the device embodiments described may beused to initially insert and position an interspinous process spacingdevice, while the securing means of the interspinous process spacingdevice may be used to achieve final fixation to the spinous processes.Though, in other embodiments, a clamping and/or insertion instrument mayhave an integrated tightening means (e.g., geared, ratchet, lever, etc.)that facilitates securing an interspinous process spacing device to thespine by tightening the clamping instrument, while the securing means ofthe interspinous process spacing device serve to secure and retain thedevice in tightened configuration.

Additional securing means embodiments are illustrated in FIGS. 8 andFIG. 10. FIG. 8B illustrates the securing means as described,incorporating two spaced apart screws 310 passing through apertures 312in the second attachment side 142 and threadably received by collars 314in the first attachment side 140. In this embodiment, the screws 310 arepositioned posterior from the spacer tray 150 and substantially withinthe diameter of the spacer tray 150, to avoid interference with thevertebrae upon implant. However, any other locations may be used asdesired. In addition, according to other embodiments, more than twoscrews can be used, or only one screw can be used.

FIG. 8C illustrates another embodiment of a securing means used totighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. In this embodiment, two spaced apart worm drive mechanismsinclude two screws 410 (i.e., the worms) passing through two apertures412 in the second attachment side 142 and operably engaging worm gearing414. The worm drive mechanisms are adapted to provide movement along theaxis of the spacer tray 150 as a result of the rotational forces appliedto screws 410 that are transferred to the adapted worm gearing 414. Inthis embodiment, instead of a traditional worm gear, a portion of theinner surfaces are toothed complementary to the screws 410. Thus, whenthe screws 410 operably engage the teeth of the worm gearing 414 on thesurface of the spacer tray 150, the screws' 410 threading passes alongthe worm gearing and causes the second attachment side 142 to move alongthe spacer tray 150. It is appreciated that, in other embodiments, theworm gearing 414 may be on any other surface of the spacer tray 150, orworm gearing separate from the spacer tray 150 may be provided. Forexample, in one embodiment, one or more screws (e.g., the worms) mayrotatably extend through the inner surface of the first attachment side140 and extend through apertures in the second attachment side 142. Inthis configuration, which is essentially reversed from theabove-described worm drive mechanism, the worm screw extending along theaxis of the spacer tray 150 is turned against a worm gear rotatablyaffixed to one of the attachment sides 140, 142, causing the secondattachment side 142 to move along the screws. Again, in any of theseembodiments, two spaced apart worm drive mechanisms permit theindependent tightening, and thus the “walking” effect when closing theattachment sides 140, 142 on the spinous processes.

FIG. 8D illustrates a side view of another embodiment of a securingmeans used to tighten opposing attachment sides 140, 142 onto adjacentspinous processes. According to this embodiment, two spur gearmechanisms include gearing teeth 420 formed on the inner or outersurfaces of the spacer tray 150, much like that described with referenceto FIG. 8C, and a shaft and gear 422 rotatably affixed to the outersurface of the second attachment side 142 that meshes with the gearingteeth 420 of the spacer tray. This embodiment behaves similar to a rackand pinion, whereby the gearing teeth 420 serve as a rack and the shaftand gear 422 serve as the pinion. Accordingly, turning each of the shaftand gears 422 causes the gears to operably mesh with the gearing teeth420 and close the second attachment side 142 toward the first attachmentside 140. It is appreciated that, in one embodiment of a spur gearmechanism (or any other securing means embodiments described herein),the shaft and gears can include a one-way or reverse lock-out mechanismto only permit rotation or movement in one direction—that which resultsin tightening the attachment sides together, but restricts movement inthe opposite direction. In some embodiments, the one-way or reverselock-out mechanisms may be selectively actuated, such that an operatormay release them (e.g., to reposition the device, to remove the device,etc.).

According to another embodiment, a mechanism configured in a mannersimilar to a rack and pinion is used. Instead of the gearing beingintegrated with a spacer tray, this embodiment includes a separategeared rack extending from the first attachment side 140 and slideablypositioned within an aperture formed in the second attachment side 142.The aperture can be sized to permit the geared rack to slide within theaperture. Also integrated or adapted with the second attachment side 142is a shaft and gear that meshes with the geared rack. This embodimentbehaves similar to a rack and pinion, whereby the shaft and gear serveas the pinion for the geared rack, advancing the second attachment side142 along the geared rack when the shaft and gear is turned, rotated, orotherwise actuated. Any one-way or reverse lock-out mechanism to permitrotation or movement in only one direction optionally can beincorporated in the securing means embodiment. In one embodiment, thegearing on both the geared rack 440 and the shaft and gear arecomplementarily angled with respect to each other, which serves to holdthe position of the shaft end gear against the geared rack whentightened and resists backing out or otherwise loosening by theattachment sides 140, 142 when secured in place.

In one embodiment the fit of the geared rack within the aperture is arelatively tight fit to reduce angular movement of the second attachmentside 142 relative to the geared rack, which may serve to reduce thepotential of cross-threading or otherwise preventing meshing of theshaft end gear with the geared rack. In other embodiments, however, thefit may be looser, allowing at least partial angular movement of thesecond attachment side 142 relative to the geared rack. A looser fit maybe used to allow the attachment sides 140, 142 to be positioned at anangle (i.e., not exactly parallel to each other) to account fordifferences in the width of adjacent spinous processes.

FIG. 10 illustrates another embodiment of a securing means used totighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. In this embodiment, a worm drive mechanism is used, similarto that described with reference to FIG. 8C. The worm drive mechanismaccording to this embodiment includes a threaded shaft 446 extendingfrom the first attachment side 140 and passing through an aperture 448in a second attachment side 142. According to one embodiment, thethreaded shaft 446 can be configured like a threaded bolt integratedwith, and extending from, the interior surface of the first attachmentside 140. The threaded shaft 446 can be fixed to the first attachmentside 140 (either integrated or bolted thereto). A worm gear nut 450 isthreadably received by the threaded shaft 446 from the outside of theattachment side 142, holding the second attachment side 142 on thethreaded shaft 446. The worm gear nut 450 includes teeth or gearing onits exterior surface which operably meshes with a screw 452 (or otherthreaded shaft operable for turning by an operator). The screw 452 actsas a worm, causing the worm gear nut 450 to rotate around the threadedshaft 446, which in turn causes the worm gear nut 450 to tighten orloosen on the threaded shaft 446. Accordingly, by rotating the screw452, such as by using a screwdriver or other instrument received by ahead of the screw 452, the worm gear nut 450 can be tightened over thethreaded shaft 446, causing the second attachment side 142 to tightentoward the first attachment side 140 over the threaded shaft 446 and aspacer tray (not shown to simplify this illustration).

In one embodiment, the fit of the threaded shaft 446 within the aperture448 is a relatively tight fit to reduce angular movement of the secondattachment side 142 relative to the threaded shaft 446, which may serveto reduce the potential of cross-threading or otherwise interfering withthe meshing of the screw 452 with the worm gear nut 450. In otherembodiments, however, the fit may be looser, allowing at least partialangular movement of the second attachment side 142 relative to thegeared member, such as may be used to allow the attachment sides 140,142 to be positioned at an angle (i.e., not exactly parallel to eachother) to account for differences in the width of adjacent spinousprocesses. Although FIG. 10 shows a particular orientation and placementof the threaded shaft 446 and the screw 452, any other orientationand/or configuration may be used.

In yet another embodiment of a securing means used to tighten theopposing attachment sides 140, 142 on adjacent spinous processes. Inthis embodiment, a worm drive mechanism is also used, similar to thatdescribed with reference to FIG. 10. However, according to thisembodiment, the threaded member extending between the first attachmentside 140 and the second attachment side 142 is configured differently.In this embodiment, the threaded member includes a fixed worm gear headpositioned on the end of the threaded member extending through theaperture in the second attachment side 142. The fixed worm gear head isin a fixed relationship relative to the threaded member, and which doesnot thread or otherwise turn independent of the threaded member. Thethreaded member of this embodiment is further configured to be receivedby and threaded into a threaded receiver, as is shown in the top viewcross-sectional illustration. A screw operably meshes with the fixedworm gear head, and is configured in the same or similar manner as isdescribed with reference to FIG. 10. Accordingly, when turning thescrew, the fixed worm gear head causes the threaded member to threadinto or out of the threaded receiver of the first attachment side 140,which in turn causes the first attachment side 140 to tighten toward thesecond attachment side 142.

According to one embodiment, the threaded member has an at leastpartially tapered end (e.g., configured as a screw), which threads intoand out of the threaded receiver. In one embodiment, a threaded memberwith a tapered end can self tap the threaded receiver; though, in otherembodiments, the threaded receiver has complementary threads alreadyformed therein. In other embodiments, the threaded member has asubstantially straight shaft with a substantially constant diameter ator near its tip (e.g., configured as a bolt). As described above, thefit of the threaded member within the aperture may be a tight or loosefit.

FIGS. 11A-11D illustrate yet another embodiment of a securing means usedto tighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. This embodiment includes a worm gear configuration, similarto those described with reference to FIGS. 10. According to thisembodiment, however, the threaded member 451 extending between the firstattachment side 140 and the second attachment side 142 is configureddifferently. In this embodiment, the threaded member 451 also includes afixed worm gear head 457 (which may also be referred to as a “gear” or“worm gear” fixed on the end of the threaded member 451 extendingthrough an aperture in the second attachment side 142 and operablymeshing with the screw 452.

However, the threaded member 451 of this embodiment is furtherconfigured to be received by and threaded into a floating receivingmember 459 retained on the exterior surface of the first attachment side140, as is shown in more detail in FIG. 11C. The floating receivingmember 459 includes a threaded orifice having threads complementary tothe threads on the surface of the threaded member 451. The floatingreceiving member 459 is retained on the exterior surface of the firstattachment side 140 by one or more pivotable retention means 461, suchas, but not limited to, retaining tabs, flanges, hooks, or other membersadapted to retain the floating receiving member 459 while still allowingpivoting, rocking, translational, and/or angular movement relative tothe attachment side 140. As illustrated in FIG. 11C, the pivotableretention means 461 according to this embodiment includes flanges ortabs 461 a extending from the floating receiving member 459 andcooperating flanges or tabs 461 b extending from the first attachmentside 140, overlapping the floating receiving member 459, and looselyfitting between the flanges or tabs 461 a, thus retaining the floatingreceiving member 459 in place. According to this embodiment, the flangesor tabs 461 a, 461 b prevent rotation of the floating receiving member459 while threading it over the threaded member 451, but still allow atleast limited pivoting, rocking, and the like due to the loose fitmentof, and play existing between, corresponding flanges or tabs 461 a, 461b. The floating receiving member 459 thus allows the first attachmentside 140 to be angled relative to the threaded member 451 (or an axisexisting between the two attachment sides 140, 142) so the attachmentsides are not required to be implanted in parallel orientation relativeto each other. Moreover, according to one embodiment, the floatingreceiving member 459 can include one or more slits formed at leastpartially along the length of the threaded portion, as shown in FIG.11C, for example, which allows spreading the threaded portion for quickinsertion of the threaded member 451 therein and subsequently pressingthe threaded portion thereby engaging the threads. In one embodimenthaving one or more slits, a quick release mechanism may be included thatspreads the spacing between the slits and disengages the floatingreceiving member 459 from the threaded member 451. In yet anotherembodiment, a floating receiving member 459 can include a threadedportion that is split and further includes a locking screw or othersimilar feature that will allow fast insertion and quick release of thedevice.

The securing means includes a screw 452 that operably meshes with thefixed worm gear head 457, such that, when turning the screw 452, thefixed worm gear head 457 causes the threaded member 451 to thread intoor out of the floating receiving member 459, which in turn causes thefirst attachment side 140 to tighten toward the second attachment side142.

As shown in FIG. 11A, the securing means according to this embodimentoptionally includes a casing 453 that at least partially (or entirely,as illustrated) encases the end of the threaded member 451 and the fixedworm gear head 457 extending from the surface of the second attachmentside 142 and providing access to the screw 452. The casing 453 canprotect the surrounding tissue from irritation or injury that may becaused by the components protruding from the interspinous processspacing device. It is further appreciated that a casing similar to thatillustrated in FIG. 11A may be included with any of the otherembodiments described herein, such as in a similar manner to at leastpartially cover components protruding therefrom (e.g., extending fromthe first and/or the second attachment sides). FIG. 11A also shows atleast one set screw 455 threadably extending through the casing 453 forengaging the threaded member 451 upon implantation (not shown forsimplicity in FIG. 11B). In other embodiments, a set screw may not beincluded, but other securing mechanisms may be used to prevent rotationor movement of the threaded member 451 and the second attachment side142 relative to each other after implant.

FIG. 11D illustrates two interspinous process spacing devices 130, 132implanted with adjacent spinous processes 120, 122, 124. Although thereis no overlap shown between the attachment sides of the two interspinousprocess spacing devices, it is appreciated that, in various embodiments,the attachment sides may overlap as further described herein.

FIGS. 12A-12B illustrate a different configuration of a nut, which maybe used to threadably receive a threaded member, like the threadedmember 451 described with reference to FIGS. 11A-11D, according to oneembodiment. The hemispherical nut 463 may be formed to have ahemispherical shape (or other shape having an at least partiallyspherical or domed shape at its apex) for rotatably and pivotallyfitting within a concave portion 465 of a first attachment side 140 ofan interspinous process spacing device. Although not illustrated inFIGS. 12A-12B, in one embodiment, the first attachment side 140 mayfurther include means for retaining the hemispherical nut with the firstattachment side, particularly during implantation, which may include,but is not limited to, one or more clips, flanges, tabs, cages, straps,bands, springs, screws, and the like. For example, according to oneembodiment, the first attachment side 140 may further include one ormore flanges or tabs similar to the flanges or tabs 461 b described withreference to FIG. 11C, which extend from the first attachment side to atleast partially overlap the hemispherical nut 463, without undulyconstraining its motion. Similarly, the hemispherical nut 463 may alsocontain one or more tabs or one or more detents adapted to cooperatewith the retaining means extending from the first attachment side 140,which will prevent the hemispherical nut 463 from rotating whenthreading a threaded member therethrough, but still allow pivoting androtation of the hemispherical nut 463.

As shown in FIG. 12A, in one embodiment, the hemispherical nut 463 mayhave one or more slits 467 formed at least partially through its body.The one or more slits 467 permit the hemispherical nut 463 to expand forrapid insertion of a threaded member and subsequent collapsing on thethreaded member to engage and secure with complementary threads 469formed through the hemispherical nut 463. In one embodiment, the one ormore slits 467 may be formed so as to extend only partially through thebody of the hemispherical nut 463, and may stop before reaching theexterior facing surface of the hemispherical nut 463. Additional inwardbiasing or tightening members, such as, but not limited to, one or morebands, springs, screws, and the like, may optionally be included to biasor force the slits 467 together and around the threaded member. Inanother embodiment, as shown in FIG. 12A, the hemispherical nut 463 maybe formed from at least two portions 463 a, 463 b (e.g., two equalhalves), which are connected at or near the exterior facing end of thehemispherical nut 463. Any means may be used to connect the two (ormore) portions 463 a, 463 b of the hemispherical nut 463, such as, butnot limited to, one or more screws, bolts, welding, tacking, clamps,bands, pins, flanges, tabs, springs, and the like. In one embodiment,one or more spring members may be contained between the two portions 463a, 463 b such that the spring member biases the portions in a moreseparated or open position and will be compressed to a more closedposition to engage the threads 469 with a threaded member when thehemispherical nut 463 is pushed into the concave portion 465 of theattachment side. FIG. 4B illustrates the first attachment side 140 fromthe interior side, showing the fitment of the hemispherical nut 463within the concave portion 465. In one embodiment, such as is shown byexample in FIGS. 4M and 4R, the receiving side of the hemispherical nut463 at or near the apex is at least partially concave to guide anddirect the threaded member into the receiving threads of thehemispherical nut. In another embodiment, a quick release mechanism mayfurther optionally be included, which will act to separate thehemispherical nut 463 to allow for unimpeded or minimally impededremoval of the threaded member from the hemispherical nut 463.

FIGS. 12C-12I illustrate yet another embodiment of a floating receivingmember configured as a hemispherical nut formed from two separatehalves. In this embodiment, as shown in FIG. 12C, a hemispherical nut490 includes a first half 490 a and a second half 490 b. According tothis embodiment, the hemispherical nut 490 includes a concave portion492 formed at its apex, which serves to guide and direct the threadedmember into the receiving threads 469 of the hemispherical nut 490. FIG.12D illustrates the exterior facing side of the hemispherical nut 490and means for retaining the two halves 490 a, 490 b together. Accordingto this embodiment, two opposing sides are recessed, creating recessedportions 493 and first and second ridges 494 a, 494 b through which acombination of screws and springs are inserted to hold the two halves490 a, 490 b together. Moreover, the recessed portions 493 provide asurface against which retaining tabs or other retaining means are placedto retain the hemispherical nut with the first attachment side, asfurther described with reference to FIG. 12I.

FIG. 12E illustrates a side view of the hemispherical nut 490 accordingto this embodiment. As shown by this side view, the second ridge 494 bincludes a pair (or any number) of aligned apertures 496 extendingthrough the ridges 494 a, 494 b. In one embodiment, each ridge 494 a,494 b further includes an additional recessed lip 497 formed with one ofthe apertures 496 for receiving and retaining a spring that creates aninward biasing force for retaining the two halves 490 a, 490 b together.In this embodiment, only a single recessed lip 497 is formed on eachridge 494 a, 494 b such that one aperture 496 has a recessed lip 497formed on the first ridge 494a, and the other aperture 496 has arecessed lip 497 formed on the second ridge 494 b and with the opposite.This allows for springs to be inserted on opposite sides of the ridges494 a, 494 b and through different apertures, as shown in FIG. 12I. FIG.12F illustrates a side profile view of the hemispherical nut 490,showing the slit formed between the two halves and the profile of thehemispherical shape and the ridges 494.

FIGS. 12G-12I illustrate a first attachment side 140 and theinteroperability of the hemispherical nut 490 therewith, according toone embodiment. FIG. 12G shows the exterior-facing surface of the firstattachment side 140, which includes a concave portion 465. The concaveportion 465 allows the hemispherical nut 490 to be pivotally androtatably housed therein, allowing for independent movement of the twoattachment sides when implanted to account for different spinous processsize and anatomy. FIG. 12H shows the interior facing side of the firstattachment side 140 with the hemispherical nut 490 contained within theconcave portion of the first attachment side 140. As described above andas is shown in FIG. 12H, the hemispherical nut 490 itself can furtherinclude a concave portion 492 that facilitates guiding a threaded membercentrally into the threads 469 of the hemispherical nut 490.

FIG. 12I illustrates the exterior-facing surface of the first attachmentside 140 having the hemispherical nut 490 retained therein. According tothis embodiment, the first attachment side includes one or moreretaining members 495 for retaining the hemispherical nut 490 within theconcave portion 465 of the first attachment side 140, such as, but notlimited to, tabs, arms, flanges, bands, screws, and the like. In thisembodiment, the retaining members 495 include two arms attached to theattachment side 140 and extending over the recessed portions 493 of eachhalf of the hemispherical nut 490. The retaining members 495 may beremovably attached to the first attachment side 140, such as via one ormore screws and the like, or may be permanently affixed or integratedwith the first attachment side 140, such as if the hemispherical nut 490and the first attachment side 140 were manufactured together, or if thehemispherical nut 490 is pressure fitted within the retaining members495. Moreover, in one embodiment, the retaining members 495 are notsecured against the recessed portions 493, but instead provide a loosefit of the hemispherical nut 490 within the attachment side 140 to allowrotating and pivoting.

FIG. 12I also illustrates screws 498 and springs 499 inserted throughthe apertures 496 of the ridges 494 a, 494 b. As is shown as one exampleconfiguration, the first ridge 494 a includes one spring 499 fit withinthe recessed lip 497 and retained by a screw 498 extending through theset of apertures and both ridges 494 a, 494 b. The second ridge 494 bsimilarly includes one spring fit within the recessed lip 497 andretained by a screw 498 extending through the other set of apertures andthrough both ridges 494 a, 494 b. According to this configuration, eachscrew 498 is inserted in opposite directions through the ridges 494 a,494 b, retaining a spring 499 on opposite sides of the hemispherical nut490. However, other screw 498 and spring 499 configurations may beprovided, or in some embodiments, a spring may not be included.

It is appreciated that, according to other embodiments, any of thefeatures described with reference to FIGS. 12B-12I may be included inany other embodiment described herein, and any other feature describedherein may be included with the embodiments of FIGS. 12B-12I. Forexample, a quick release mechanism may be included, other floatingreceiving member configurations may be used, and the like.

FIG. 12J illustrates yet another embodiment of a securing means used totighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. This embodiment is configured similar to the embodimentillustrated in and described with reference to FIG. 10; although,instead of an integrated shaft and gear to drive the nut, a removableinstrument 460 is used to engage and rotate a geared nut 462 threadedover an end of the threaded shaft 446. Because the instrument 460 isremovable and not integrated with the interspinous process spacingdevice, an additional positioning track 464 is integrated with thesecond attachment side. The positioning track 464 guides the instrument460 to align its geared tip 466 with the teeth extending from thesurface of the geared nut 462. Although the positioning track 464 isillustrated as being configured in an L shape, any other trackconfiguration may be used. For example, in another embodiment, thepositioning track 464 may be configured as a hole aligned to cause thegeared tip 466 to mesh with the geared nut. Moreover, in one embodiment,the positioning track 464 may be formed with thick side walls tofacilitate maintaining alignment of the instrument 460 within thepositioning track and in a vertical (or other desirable) orientation byproviding increased surface area to guide the instrument 460.Accordingly, operably meshing the geared tip 466 of the instrument 460with the geared nut 462 and turning the instrument causes the geared nut462 to thread on and off of the threaded shaft 446, moving the secondattachment side 142 toward the first attachment side.

As described above, the fit of the threaded shaft 446 within theaperture of the second attachment side 142 may be a tight or loose fit.In addition, although FIG. 12J shows a particular orientation of thethreaded shaft 446 and the positioning track 464, any other orientationand/or configuration may be used.

FIG. 12K illustrates yet another embodiment of a securing means used totighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. According to this embodiment, a geared rack 470 and a ratchetmember 472 operate in a manner similar to known cable tie mechanisms. Inthis embodiment, the geared rack 470 extends from the first attachmentside 140 through an aperture 474 formed through the second attachmentside 142. The second attachment side 142 includes a ratchet member 472formed on at least one of its surfaces (shown on the outward-facingsurface, but may be on the inward surface in other embodiments). Theratchet member 472 operably engages with the teeth on the geared rack470 and permits movement in one direction—the direction toward theopposing attachment side 140. The operation of the ratchet member 472,however, restricts movement in the opposite direction (e.g., looseningof the attachment sides 140, 142). In one embodiment, a releasemechanism may be included to selectively allow movement in the oppositedirection. Accordingly, by tightening the second attachment side 142toward the first attachment side 140, the ratchet member 472 secures theposition of the two sides relative to each other. In one embodiment, aseparate insertion instrument (e.g., pliers-type device) is used toachieve enough mechanical advantage to tighten the attachment sides 140,142 on the spinous processes. An example of such a clamping device isillustrated in and described with reference to FIGS. 13-20 below.

According to one embodiment, the geared rack 470 may be slideablypositioned through both an aperture 478 formed in the first attachmentside 140 and the aperture 474 of the second attachment side 142, havinga head 476 on one end which will abut the outer surface of the firstattachment side 140. In one embodiment, the head 476 is domed on theside that will abut the attachment side (i.e., adjacent to the shaft),which permits the geared rack 470 to rotate at least partially withinthe aperture 478 and allow the two attachment sides 140, 142 to vary intheir angular orientation relative to each other and relative to thegeared rack 470. In one embodiment, the aperture 478 of the firstattachment side 140 is also beveled or bored to accommodate the domedshape of the geared rack 470. Moreover, in one embodiment, the aperture474 formed in the second attachment side 142 can form a relatively tightfit with the geared rack 470 to provide secure engagement of the ratchetmember 472 against the geared rack 470. An aperture 474 creating a tightfit causes the second attachment side 142 to have a substantiallyconstant angular relationship with the geared rack 470 (e.g.,perpendicular); however, a looser fit between the head 476 and theaperture 478 in the first attachment side 140 still allows relativeangular variation between the two attachment sides (e.g., to accommodatedifferent thicknesses of adjacent spinous processes).

In addition, although FIG. 12K shows a particular orientation of thegeared rack 470 and the ratchet member 472, any other orientation and/orconfiguration may be used.

FIG. 12L illustrates yet another embodiment of a securing means used totighten the opposing attachment sides 140, 142 on adjacent spinousprocesses. According to this embodiment, a geared cam 480 is actuated bya shaft and gear 482 operably meshed with the geared cam 480 to causethe lobe of the cam to exert a force against a second attachment side142, in turn causing it to move toward the first attachment side 140.According to this embodiment, a track 484 (which may be a spacer tray ora separate track) extends from the first attachment side 140 and throughan aperture 486 in the second attachment side 142. The geared cam 480 ispivotally fixed to the track 484 via an axle running through the cam480. Thus, when the shaft and gear 482 is turned, the cam 480 rotatesabout the axle and the lobe of the cam 480 moves toward or away from theouter surface of the second attachment side 142, causing the secondattachment side 142 to move along the track 484 toward or away from thefirst attachment side 140.

As described above, the fit of the track 484 (and/or spacer tray) withinthe aperture of the second attachment side 142 may be a tight or loosefit. In addition, although FIG. 12L shows a particular orientation ofthe geared cam 480, the threaded member track 484, and the shaft andgear 482, any other orientation and/or configuration may be used.

Although not illustrated in every figure, any of those securing meansillustrated may further include one or more set screws, securing thesecond attachment side 142 (or whichever attachment side slides over thespacer tray 150) to the spacer tray 150 or the geared rack, threadedmember, threaded bolt, track, etc. when tightened to fix the relativelocation of the two attachment sides 140, 142. A set screw assembly canextend from the outer surface of the second attachment side 142 andthrough which a set screw is threaded to exert pressure on, and thus tosecure the attachment side 142 to, the spacer tray 150. In otherembodiments, more than one set screw assembly can be employed. Moreover,the orientation of the set screw assembly can vary.

In addition, although the embodiments illustrated show the securingmeans oriented as generally extending from the first attachment side 140and through the second attachment side 142, it is appreciated that inother embodiments the opposite configuration can be provided, in whichthe securing means extends from the second attachment side 142 andthrough an aperture formed through the first attachment side 140.

FIGS. 13-20 illustrate embodiments of a separate insertion instrument(implant inserter) 1110 that is optionally used to exert a clampingpressure on each of the attachment sides 140, 142 when securing theinterspinous process spacing device in place against the spinousprocesses. In one embodiment, the attachment sides 140, 142 may includeapertures or indentations shaped and positioned to receive the workingends of the insertion instrument 1110, such that the insertioninstrument 1110 may grasp the attachment sides 140, 142, and operable tofacilitate aligning and maintaining the insertion instrument 1110 inposition. Accordingly, once the two attachment sides 140, 142 areclamped in a closed configuration, the securing means 1120 (e.g., any ofthose illustrated in and described with reference to FIGS. 1-12 and,optionally or alternatively, a set screw) is operated to secure thesecond attachment side 142 in place relative to the spacer tray 150 andthe first attachment side 140. It is appreciated that any insertioninstrument 1110 suitable for applying a clamping force on oppositeattachment sides may be used.

For example, FIGS. 13-16 illustrate another embodiment of an insertioninstrument 1130 having a different configuration. According to thisembodiment, a second arm 1134 is removably attached to a first arm 1132of the insertion instrument 1130. Thus, during implantation, the firstarm, which retains one of the first or the second attachment sides 140,142, is used to place the one side of the device against the spinousprocesses via an approximate lateral insertion angle, after which thesecond arm 1134, which retains the other attachment side, is attached tothe first arm and pivots to place the other attachment side against theopposite side of the respective spinous processes, also laterally fromthe opposite side. Thus, an insertion instrument 1130 according to thisembodiment reduces the size of the incision by allowing positioning oneattachment side first using a separated first arm 1132. Otherwise, ifthe two arms 1132, 1134 are attached prior to implant, the insertioninstrument 1130 has to open almost twice as wide to permit insertingboth attachment sides laterally while the spinous ligament is stillintact.

FIGS. 13-16 show an example surgical instrument system for implanting aninterspinous process spacing device, having a first arm 1132 having aproximal end, an elongated central portion and distal end. The distalend has an interspinous process spacing device engagement element 1162for posteriorly engaging a spacer plate or first attachment side 140 ofthe interspinous process spacing device having a spacer tray 150extending inwardly therefrom. The surgical instrument system has asecond arm 1132 having a proximal end, an elongated central portion anddistal end, wherein the distal end has an interspinous process spacingdevice engagement element 1164 for posteriorly engaging a locking plateor second attachment side 1142 of the interspinous process spacingdevice having a spacer tray slot 135 therein for receiving the spacertray 150.

The surgical instrument system has a means for positioning the first arm1132 and the second arm 1134 in alignment for securing the interspinousprocess spacing device onto spinal processes. As discussed in moredetail below, the means for positioning the first arm 1132 and thesecond arm 1134 in alignment can be along any portion of the arms 1132,1134, including at a hinge in the central portion or by a connectingmember at the proximal portion, such as a latch or ratchet. As can beseen in this embodiment, the proximal and distal ends of the arms 1132,1134 are offset to provide an unobstructed view of the distal ends whena surgeon is holding the proximal ends.

In the illustrated embodiment of the surgical instrument system forimplanting an interspinous process spacing device, each arm 1132, 1134has an interspinous process spacing device engagement element 1162, 1164which has an engagement projection 1170, 1180 which releaseably engagesan instrument receptacle on the attachment side 140, 142 respectively,of the interspinous process spacing device, a mount 1172, 1182 formovably holding the engagement projection, and an implant guide 1174,1184 extending distally which engages the outer surface of theattachment sides of the interspinous process spacing device.

As shown in FIGS. 13-16, the engagement projections 1170, 1180 arethreaded screws which rotatably ride in the mount 1172, 1182 forengagement with the separate attachment sides 140, 142 of theinterspinous process spacing device. The threaded projections arecontrolled by thumbscrews 192, 194, which can also be remotely operatedby a ratchet or other rotatable tool.

In the illustrated embodiment, each arm 1132, 1134 permits at least oneof an engaged attachment side 140, 142 of the interspinous processspacing device at least 5 degrees, or at least 10 degrees, and up to 30degrees, of rotation about an axis defined by the engagement element1174, 1184 on the distal end of the arm 1132, 1134. This permittedwobble of each or both of the attachment sides allows for implanting thedevice onto spinous processes with varying shapes and contours prior tosecuring the desired relative orientation by engaging the securing means320 (e.g., a set screw) onto the spacer tray 150.

In the illustrated embodiment, the engagement projection 1180 on thesecond arm 1134 provides access to the securing means on the secondattachment side 142 of the interspinous process spacing device to securethe second side 142 to the first side 142. In the embodiment shown, theengagement projection 1180 includes a threaded screw which engages areciprocal threaded instrument receptacle on the attachment side 142 ofthe interspinous process spacing device. However, the threaded screw onthe second arm 1134 is cannulated to provide access therethrough to thesecuring means on the second attachment side 142 of the interspinousprocess spacing device to secure the second side 142 to the first side140 while the second side 142 is engaged to the second arm 1134. Thecannulation permits a surgeon to use a separate securing instrumentextending through the engagement element 1164 to secure the implantabledevice onto a spinous process.

In certain embodiments of the surgical instrument system for implantingan interspinous process spacing device, the size, shape or indicia oneach of the insertion instrument receptacle on the first attachment sideis different from the size, shape or indicia of the insertion instrumentreceptacle on the second attachment side. In a coordinated manner, thesize, shape or indicia on the device engagement element 1162 correspondsto that of the first attachment side 140, and is different from thesize, shape or indicia on the device engagement element 1164 whichcorresponds to that of the second attachment side 142. As shown theengagement element 1162 has a single laser etch mark to match the secondattachment side 142, and the engagement element 1164 has a double laseretch mark to match the first attachment side 140.

In the illustrated embodiment, the proximal ends of the first and secondarms 1132, 1134 are releasably connectable at more than one selecteddistance. In particular, the central portions of the first and secondarms 1132, 1134 are releasably and rotatably connectable. In suchembodiments, the second arm 1134 is removably and pivotally attachableto the first arm 1132 about an axis for positioning the first arm 1132and the second arm 1134 in alignment for securing the interspinousprocess spacing device onto spinal processes.

As shown, the second arm 1134 further comprises a pivot member or pin1137 located on the central portion, and the first arm 1134 furthercomprises a pivot channel or slot 1135 with a proximally orientedopening and a distally oriented curved retaining edge 1136, such whenthe pin 1137 is slideably engaged in the slot 1135 against the retainingedge 1136 the first and second arms 1132, 1134 are removeably andpivotally attached to form a hinge, wherein the hinge permitspositioning the first arm 1132 and the second arm 1134 in alignment forsecuring the interspinous process spacing device onto spinal processes.

In use, when the first and second arms 1132, 1134 each have a respectivefirst and second attachment side 140, 142 of the interspinous processspacing device engaged thereto, and the first and second arms 1132, 1134are attached at the hinge, drawing the proximal ends of the armstogether will align and insert the spacer tray 150 into the spacer trayslot 210 of the first and second attachment sides 140, 142 of theinterspinous process spacing device, for securing the interspinousprocess spacing device onto spinal processes.

As shown in FIGS. 13-16, the first arm 1132 further comprises areleasable locking mechanism for selectively securing the pin 1137 ofthe second arm 1164 into the slot 1135 of the first arm 1132. In certainembodiments, the releasable locking mechanism is a leaf spring 1139 onthe central portion of the first arm 1132 in blocking communication withthe slot 1135, such that the pin 1137 on the second arm 1164 can deflectthe leaf spring 1139 during insertion into the slot 1135 and remaintherein when the leaf spring 1139 returns to blocking communication tomaintain the pin 1137 against the retaining edge 1136 on the first arm1132, and wherein the leaf spring 1139 can be manually disengaged fromblocking communication with the slot 1135 to release the pin 1137 andseparate the first and second arms 1132, 1134.

As illustrated, the surgical instrument system for implanting aninterspinous process spacing device has a means for mechanicallyactuating the insertion instrument to close and open the first arm 1132and the second arm 1134 for tightening the second attachment side 142relative to the first attachment side 140. In certain embodiments, themeans for mechanically actuating is a ratchet bar 1190 pivotally mountedto the proximal end of the second arm 1134 and selectively engageable tothe proximal end of the first arm 1132, wherein the ratchet bar 1190 hasa plurality of teeth 1195 on the proximal surface thereof which engage acorresponding flange 1296 on the proximal end of the first arm 1132. Theratchet bar 1190 has a threaded track and a nut 1192 riding thereonoutside the proximal end of the first arm for mechanically forcing theproximal ends of the arms 1132, 1134 together.

According to the embodiment of FIGS. 13-16, the first arm 1132 mayinclude a pivot channel 1135 which is at least partially open to receiveand retain a pivoting member 1137 extending from the second arm 1134.Although an angled pivot channel 1135 is illustrated, the pivot channel1135 may be embodied in any number of other various shapes,configurations, and/or dimensions that allow removably attaching andsecuring the second arm 1134 to the first arm 1132 and that allow thetwo to pivot relative to each other. To attach the second arm 1134 tothe first arm 1132 after one attachment side has been inserted into thepatient, the pivoting member 1137 of the second arm 1134 is insertedinto and guided through the pivot channel 1135 and rests at the distalend of the pivot channel 1135 where it is secured but allowed to pivot(e.g., similar to separable shears). Therefore, only the second arm 1134is pivoted toward the first arm 1132 to insert the other attachmentside, while the first arm 1132 remains stationary.

With reference to FIGS. 17-20, the present invention further provides anembodiment of a surgical instrument system for implanting aninterspinous process spacing device, comprising a first arm 1232 havinga proximal end, an elongated central portion and distal end, wherein thedistal end has an interspinous process spacing device engagement element1262 for posteriorly engaging a spacer plate or first attachment side140 of the interspinous process spacing device having a spacer tray 150extending inwardly therefrom. Such an embodiment also has a second arm1234 having a proximal end, an elongated central portion and distal end,wherein the distal end has an interspinous process spacing deviceengagement element 1264 for posteriorly engaging a locking plate orsecond attachment side 142 of the interspinous process spacing devicehaving a spacer tray slot 210 therein for receiving the spacer tray 150.This embodiment further includes a compressor tool 1200 for positioningthe first arm 1232 and the second arm 1234 in alignment for securing theinterspinous process spacing device onto spinal processes.

As illustrated, the compressor tool 1200 has a proximal handle end acentral portion and a distal pair of opposing tangs 1222, 1224 moveablethroughout a range between an open position and a compression position.In certain embodiments, the distal end of each arm 1232, 1234 comprisescompressor tool guide channels 1242, 1244 and compression pointindentations 1246, 1248 therein for receiving the compressor tool tangs1222, 1224. In certain embodiments, the tangs 1222, 1224 have distalcompressor tips 1252, 1254 extending inwardly for engagement within thecorresponding guide channels 1242, 1244 and compression pointindentations 1246, 1248 on the arms 1232, 1234, wherein the compressiontool 1200 can rotate about an axis defined by the compressor tips 1252,1254 so as to provide a user with a range of approach angles forcompressing the arms 1232, 1234 to secure the aligned interspinousprocess spacing device onto spinal processes.

In the illustrated embodiment of the surgical instrument system forimplanting an interspinous process spacing device, the proximal end ofthe second arm 1234 further comprises a retaining latch 1280 disposableon the distal end of the first arm 1232 to retain the arms in positionrelative to each other and in alignment for securing the interspinousprocess spacing device onto spinal processes. The latch 1280 can have aseries of corresponding indentations for engagement on the first arm1232.

In certain embodiments, the surgical instrument system for implanting aninterspinous process spacing device has a means for mechanicallyactuating the insertion instrument to close and open the first arm 1232and the second arm 1234 for tightening the second attachment side 142relative to the first attachment side140. As shown, the means formechanically actuating is a ratchet bar 1290 pivotally mounted to theproximal end of the second arm 1234 and selectively engageable to theproximal end of the first arm 1232, wherein the ratchet bar 1290 has aplurality of teeth 1295 on the proximal surface thereof which engage acorresponding flange 1296 on the proximal end of the first arm 1232. Theratchet bar 1290 has a threaded track and a nut 1292 riding thereonoutside the proximal end of the first arm 1232 for mechanically forcingthe proximal ends of the arms 1232, 1234 together.

The insertion instrument can further include a flattened surface at ornear the pivot point of the instrument. The flattened surface is adaptedfor striking with a mallet or tamp during insertion of the device toseat each attachment side. It is appreciated that, while the flattenedsurface can be integrated with the first arm of the insertioninstrument, in other embodiments, a flattened surface may be integratedwith another portion of the insertion instrument; however, it may bedesirable to orient the flattened surface substantially above the devicewhen implanted.

Moreover, according to alternative embodiments, the insertion instrumentcan further include one or more channels or partial channels (e.g., C-or U-shaped channels, etc.) formed in at least one of the arms throughor alongside of which a tightening instrument (e.g., a screwdriver) canbe inserted to operate the securing means. For example, according to oneembodiment, the first arm includes a channel running at least partiallyalong the length of the first arm. The orientation of the channeldirects the tightening instrument through the channel to align with thesecuring means. For example, if the securing means includes a screw orother rotating mechanism, the insertion instrument can be configuredsuch that when aligned with and attached to the interspinous processspacing device, the first channel aligns with the head of the screw orother rotating mechanism. In other embodiments, one or more additionalchannels may be formed in an arm of the insertion instrument, such thatthe additional channel or channels align with a set screw used to fixthe position of the second attachment side relative to the firstattachment side. In yet another embodiment, a rotating channel, whichmay be formed as a sleeve that rotates around the axis of the first arm,and indexed to stop at the desired orientations, is used to align withboth the securing means and the set screw. In other embodiments, asingle channel may be used to align a tightening instrument byre-positioning the arm of the insertion instrument to achieve thedesired alignment.

As shown in FIGS. 13-16, the distal portion of each of the arms 1132,1134 of the insertion instrument 1130 further includes a retaining means1162, 1164, respectively, for grasping or otherwise retaining therespective attachment side during implantation. In one embodiment, theretaining means on the first arm 1132 includes a first peg having anon-circular cross-sectional shape, such that it is insertable into acorrespondingly shaped orifice formed in the respective attachment side(e.g., the second attachment side 142) and provides a friction fit forretaining the attachment side to the first arm 1132. The non-circularshape prevents the attachment side from rotating on the first arm 1132during implantation. In this embodiment, the retaining means on thesecond arm 1134 may include a second peg or pin having a circularcross-sectional shape, which is also insertable into a correspondinglyshaped orifice formed in the respective attachment side (e.g., the firstattachment side 140). Thus, during implantation, while the secondattachment side 142 is in a fixed orientation when retained by theinsertion instrument 1130, the first attachment side 140 can rotate,which allows for easier alignment of the spacer tray extending from thefirst attachment side 140 into the slot of the second attachment side142 and alignment of the securing means (e.g., threaded member)extending from the second attachment side into the receiving means(e.g., floating nut or hemispherical nut) of the first attachment side.In some embodiments, the floating, rotating, and/or pivoting behavior ofthe receiving means (e.g., floating nut or hemispherical nut) and theadvantageously shaped interior surfaces (e.g., a concave shape, etc.)improve the ability to align the spacer tray and/or securing means whilebringing the two sides together. It is appreciated that any other meansfor retaining attachment sides by the insertion instrument 1130 may beincluded, such as, but not limited to, one or more clips, brackets,clamps, releasable straps, and the like. For example, in anotherembodiment, the distal ends of each arm 1132, 1134 may be formed in aC-shaped or bracket-shaped clamp, within which a respective attachmentside is retained.

It is appreciated that the insertion instrument configurations describedherein are provided for illustrative purposes, and that any otherconfiguration and any other orientation relative to the interspinousprocess spacing device may be used. For example, according to oneembodiment, tightening or clamping means similar to any of the securingmeans described, or any variation thereof, may be integrated with aninsertion instrument and between the two arms. In this embodiment, afterpositioning an interspinous process spacing device to a patient'sspinous processes, the tightening or clamping means may be used totighten the device and secure it to the spinous processes, while othersecuring means on the device (e.g., those described, or simpler means,such as a set screw, ratchet, pin, screw, etc.) can be used to retainthe device in its secured position. It is appreciated that, in someembodiments, clamping or tightening means integrated with a clampinginstrument may differ from those described, and may include one or morescrews, one or more ratchets, one or more levers, one or more gearedmechanisms, and the like.

In addition, it may be advantageous to provide two different insertioninstruments, one configured for an interspinous process spacing devicebeing implanted in one orientation and the other configured for aninterspinous process spacing device being implanted in the oppositeorientation. According to some embodiments, as described herein, atleast one arm of an insertion instrument may include featuresspecifically designed to interface with a particular attachment side(e.g., the first retaining means 1162 configured specifically forretaining the second attachment side 142 and the second retaining means1164 configured for retaining the first attachment side 140, or thechannel 1140 oriented to align with the worm gear screw of the securingmeans, etc.). Thus, without reconfiguring the orientation of thesefeatures and without changing the orientation of the handles, aphysician would have to change sides of the patient when implantingdevices having opposite orientations, which is very impractical andhighly undesirable. For example, the screw driving the worm gear in thefirst and second interspinous process spacing devices are on one side,while the screw of the third interspinous process spacing device is onthe opposite side. Accordingly, to prevent the physician from having toswitch patient sides during implantation, a second insertion instrumentcan be formed as essentially the mirror image of the insertioninstrument illustrated and described, such that the handles would beoperated from approximately the same angle, but the features of theinsertion instrument operably align with the device as designed.

However, in another embodiment, a universal insertion instrument may beprovided, such that the retaining means extending from the distal endsof each arm of the instrument is configured to have substantially thesame shape and orientation. Thus, the retaining means will integratewith either attachment side of an interspinous process spacing device,regardless of the device's orientation. For example, one way to achievethis universal fitment of the insertion instrument is with two pinsextending from the distal ends of each attachment arm, the pins beingconfigured the same on each arm. The first attachment side (e.g., theside that does not include the securing means, such as with a floatingnut or other receiving member) can be configured with a complementaryorifice for receiving one of the two pins while the other pin does notengage or interfere with the first attachment side. The secondattachment side, however, can be configured with two complementaryorifices such that the two pins are insertable into the two orifices.When installing the second attachment side, both pins are insertedtherein, and when installing the first attachment side, only one pin isinserted while the other pin hangs free of the first attachment side.Thus, the operator need not switch between insertion instrumentsdepending upon the orientation of the interspinous process spacingdevice being implanted.

The present invention also provides a surgical instrument for selectingan interspinous process spacing device, as exemplified in FIGS. 21A-21B.The selection instrument 800 comprises a first arm 810 having a proximalend, an elongated central portion and distal end, wherein the distal endhas a first interspinous process spacing measurement wing 814 extendingtherefrom comprising a first spinous process stop element 812 and aperpendicularly extending wing template 816, a second arm 820 having aproximal end, an elongated central portion and distal end, wherein thedistal end has a second interspinous process spacing measurement wing824 extending therefrom comprising a second spinous process stop element822 and a perpendicular wing template 826. The first and second arms810, 820 are pivotally attached about an axis 830 for positioning thefirst and second interspinous process spacing measurement wings 814, 824to measure space between adjacent spinal processes.

The measurement device 800 can further comprise first and second wingtemplates 816, 826 adapted to overlap respective first and secondadjacent spinal processes to determine space available on each spinousprocess for engaging an interspinous process implant. The instrumentshown is adapted such that the proximal end of the second arm 820 has ameasuring element 840 attached thereto with indicia to register lengthto the proximal end of the first arm 810, wherein said lengthcorresponds to space between adjacent spinal processes as measured bythe first and second spinous process stop elements 812, 822. Therefore,drawing the proximal ends of the arms 810, 820 together separates thewings 814, 824 to measure space between adjacent spinal processes. Inone embodiment, the first or second wing template, or both, comprises afastener template extending therefrom adapted to engage with a slot onan attachment side of an interspinous process spacing device previouslyimplanted to determine space and orientation available for overlappingengagement of a link plate onto a base plate.

FIG. 1 illustrates further detail of a top perspective view ofembodiments of interspinous process spacing devices implanted in anoverlapping fashion. FIG. 1 shows a first interspinous process spacingdevice 130 having substantially flat attachment sides 140, 142, which isillustrated in FIG. 1 as being the one inferiorly located device, suchas any of the interspinous process spacing devices illustrated in anddescribed with reference to FIGS. 2-12. In addition, according to someembodiments of the invention, a second (and subsequent) interspinousprocess spacing device 132 is implanted on adjacent spinous processes,which includes attachment sides 144, 146 having a bent configuration.According to one embodiment, the bent configuration is created by havinga substantially flat end 148, which, when implanted, will lie alongapproximately the same plane as the entire attachment side of theadjacent inferior interspinous process spacing device (e.g., theattachment sides 140, 142 of the first interspinous process spacingdevice 130 per FIG. 1), and an offset end 149, which will overlap theadjacent end of the inferior (or superior, though not illustrated inthis manner) interspinous process spacing device. The offset of theoffset end 149 can be approximately equal to, or slightly larger orsmaller than, the thickness of the anticipated adjacent attachment side(e.g., the thickness of an attachment side 140, 142 of the firstinterspinous process spacing device 130).

Accordingly, at least one end of each attachment sides 140, 142 of thefirst interspinous process spacing device 130 and the offset end 149 ofthe second interspinous process spacing device 132 includes anintegration means for integrating an offset end 149 of the secondinterspinous process spacing device 132 with a respective attachmentside of the first interspinous process spacing device. The embodimentincludes an integration means having one or more apertures 240 formed inthe outer surface to receive at least a portion of fasteners 220extending from the inner surfaces of the offset ends 149 of therespective attachment sides 144, 146. The fasteners 220 of the offsetends extending through the apertures 240 can be interlocking posts or beextended sharpened bone fasteners, such as spikes, for engaging aspinous process through the aperture. The apertures 240 permit theattachment sides 144, 146 of the second interspinous process spacingdevice 132 to integrate and interlock with the attachment sides 140, 142of the first interspinous process spacing device 130.

According to one embodiment, the number of apertures 240 in the firstinterspinous process spacing device 130 equals the number of fasteners220 extending from the second interspinous process spacing device 132.However, in other embodiments, there may be more apertures 240 thanfasteners 220 to allow for selective adjustment of the relativeorientation of the two interspinous process spacing devices 130, 132 byselecting from multiple positions created by the various aperturelocations 240. Apertures may be provided in an overlapping or inch wormpattern for finer adjustments of spacing and angles between each pair ofspacing plates. Moreover, in one embodiment, the apertures 240 andcorresponding fasteners 220 may have a turning/locking configuration,such that the fasteners 220 can selectively lock (e.g., by turning,snapping, etc.) within the apertures 240 when in position. In addition,the apertures 240 may be sized and shaped larger than the diameter ofthe corresponding fasteners 220, to permit adjusting the position andorientation of the second interspinous process spacing device 132relative to the already secured first interspinous process spacingdevice 130. In other embodiments, however, the apertures 240 may be anyconfiguration. Moreover, in one embodiment, slots may not be provided,and the offset ends 149 of the attachment sides 144, 146 may not includefasteners, but instead may include a rough surface, or other suitablemeans to secure the two attachment sides. Although only a first and asecond interspinous process spacing devices 130, 132, in otherembodiments additional interspinous process spacing devices may be addedto the second interspinous process spacing device 132 in a similarmanner to connect additional spinous processes. Each subsequentinterspinous process spacing device would be configured similar to thesecond interspinous process spacing device 132, including offset ends149 to overlap with the flat ends 148 of the adjacent interspinousprocess spacing device. To permit adding another interspinous processspacing device to the second interspinous process spacing device 132,the outer surfaces of the flat ends 148 of the attachment sides 144, 146also include apertures 240 to receive fasteners, like those shown on thefirst interspinous process spacing device 130, or any other integrationmeans. Any number of interspinous process spacing devices can beintegrated together, permitting fusing a number of spinous processes andproviding increased structural integrity over individually andun-integrated known spinous process spacing devices.

For example, in one embodiment in which three interspinous processspacing devices are attached. In this embodiment, the first interspinousprocess spacing device has substantially flat attachment sides, and thesecond and third interspinous process spacing devices have bentattachment sides with offset ends for overlapping adjacent devices. Inthis embodiment, the first interspinous process spacing device isimplanted, after which the second and third interspinous process spacingdevices are implanted such that each overlaps with a different end ofthe first interspinous process spacing device (e.g., one implantedsuperior to and the other implanted inferior to the first interspinousprocess spacing device). As shown, the second and third interspinousprocess spacing devices are oriented 180 degrees relative to each otherto allow the offset ends of the bent attachment sides to overlap theattachment sides of the first interspinous process spacing device,depending upon whether being attached superior to or inferior to thefirst interspinous process spacing device. Thus, rotating the subsequentinterspinous process spacing devices, if necessary, avoids having tomanufacture two different interspinous process spacing deviceconfigurations—one for attaching superior to a flat device and one forattaching inferior to a flat device. Because the location of thesecuring means may differ when an interspinous process spacing device isrotated, different insertion instruments may be provided to accommodatethe differing orientations of the device components.

In another embodiment, in which a stub implant is provided, instead of afirst interspinous process spacing device. The stub implant simplyconsists of two stub sides proportioned to engage a single spinousprocess, and not intended to span two adjacent spinous processes.Accordingly, instead of attaching a second interspinous process spacingdevice to a first device, it is attached to a stub implant. Inoperation, the second interspinous process spacing device and the stubimplant are likely implanted together, as the two stub sides are securedby the pressure exerted by the second interspinous process spacingdevice. Like the other interspinous process spacing devices, the stubsides can also include fasteners extending from their inner surfaces forsecuring to the spinous process, and apertures formed in their outersurfaces for receiving fasteners of the overlapping interspinous processspacing device, or any other integration means. This embodiment mayserve to reduce the manufacturing costs, requiring only a single designfor the interspinous process spacing device, and smaller, much simplerdesign for the stub implant.

FIGS. 7A-7E illustrate other example embodiments of an interspinousprocess spacing device that is configured for implanting at the L5-S1vertebrae. As shown, an L5-S1 interspinous process spacing device 530includes first and second attachment sides 540, 542, each having anangled end 545 and an opposite flat end 547 with various spiked bonefasteners 525 extending inwardly. The angled ends 545 allow better fitwith the anatomy of a patient's sacrum. In certain embodiments notshown, the angled ends may be further adjustable with respect to thecentral portion of the device to match the angle on the patient'ssacrum. The L5-S1 interspinous process spacing device 530 may includeany securing means, such as are illustrated in and described herein, andany integration means. Moreover, in a base plate embodiment such as thatillustrated in FIGS. 7A-7C with apertures 550 in the flat end 547, anadditional interspinous process spacing link device can be implantedsuperior to the L5-S1 interspinous process spacing device 530 in anoverlapping configuration by overlapping bent attachment sides of thesuperior interspinous process spacing device with the flat ends 547 ofthe L5-S1 interspinous process spacing device 530. However, in a linkplate embodiment such as that illustrated in FIGS. 7D-7E, with fasteners520 on an offset flat end 547, the L5-S1 interspinous process spacingdevice 530 has bent attachment sides such that the ends opposite theangled ends 545 are offset and overlap flat ends of a superiorinterspinous process spacing device. In certain embodiments, the bonefasteners 525 extend from opposing plates toward the bone at differentopposing points to reduce the risk of bone fracture.

FIG. 7B illustrates a view of a second attachment side 542 of an L5-S1interspinous process spacing device 530. As shown, the angled end 545 ofthe second attachment side 542 may optionally include one or moreapertures 550 for receiving one or more fastening means therethrough.Because the sacrum is typically more dense than spinous processes, onemeans to secure an L5-S1 interspinous process spacing device 530 to thesacrum includes fastening directly thereto through the one or moreapertures 550, such as via screws, set screws, and the like. Inparticular, an angled fastener 555 can be provided at an angle differentfrom the angle at which other fasteners 525 extend. In some embodimentssuch as shown, the angled fastener 555 is a bone screw and the otherbone fasteners 525 are bone spikes, although any combination of movable,immovable, or expandable bone fasteners can be used.

FIG. 7A illustrates a side view of the interior surface of a secondattachment side 542 of a L5-S1 interspinous process spacing device 530.In this embodiment, one or more fasteners 525, similar to the fasteners225 described with reference to FIG. 2A, extend from the interior of theangled end 545 of the L5-S1 interspinous process spacing device 530.However, because of the orientation of the angled end 545 relative tothe patient's sacrum, the fasteners 525 may extend at an angle otherthan 90 degrees (either acute or obtuse), such that they correctlyengage the sacrum when tightening the two attachment sides together. Itis appreciated that the second attachment side 542 is described andillustrated in detail by example, but that the first attachment side 540may also include one or more apertures and one or more fasteners.

The integration means of certain embodiments includes a textured innersurface formed on the inner surface of the offset end and a texturedouter surface formed on the outer surface of an adjacent flat end (onthe same interspinous process spacing device or understood that theoffset end of one interspinous process spacing device will overlap aportion of the flat end of an adjacent interspinous process spacingdevice). According to one embodiment, the textured inner surface hasradially extending ridges arranged in a starburst or spoked pattern.Similarly, the textured outer surface can have one or more detents ornubs (or other surface patterns) approximately matching the radiallyextending pattern of the textured inner surface. The textured outersurface has multiple complementary detents to permit selectivearrangement of the offset end in more than one position. It isappreciated that, while a radially extending pattern is described, anyother textured surface may be applied to the inner and outer texturedsurfaces.

Moreover, according to one embodiment, the inner surface of the offsetend may further include a pin extending inwardly, which can be at leastpartially inserted into one or more apertures formed in the outersurface of the flat end of the adjacent interspinous process spacingdevice. The pin can be positioned approximately in the center of theradially extending ridges and three apertures are formed in the flat endapproximately in the center of the corresponding radial detents. It isappreciated that any number of pins and any number of apertures may beprovided. Moreover, any other orientation of the pins and/or theapertures may be used. For example, according to another embodiment, theapertures may be formed in two dimensions to allow for bothanterior/posterior and superior/inferior adjustment.

The interspinous process spacing devices and any associated componentsmay be made of any suitable biocompatible material, including, but notlimited to, metals, resorbable ceramics, non-resorbable ceramics,resorbable polymers, non-resorbable polymers, and/or any combinationand/or alloys thereof. Some specific examples include stainless steel,titanium and its alloys including nickel-titanium alloys, tantalum,hydroxylapatite, calcium phosphate, bone, zirconia, alumina, carbon,bioglass, polyesters, polylactic acid, polyglycolic acid, polyolefins,polyamides, polyimides, polyacrylates, polyketones, fluropolymers,and/or other suitable biocompatible materials and/or combinationsthereof.

In use, an example method of implanting at least two interspinousprocess spacing devices can be understood with reference to FIGS. 1-21.In one embodiment, after gaining access to the surgical implantationsite, and removing all necessary tissue, the second attachment side 142of a first interspinous process spacing device 130 is attached to asecuring means 1162 of the first arm 1132 of an insertion instrument1130 prior to attaching the second arm 1134 to the insertion instrument1130. The first arm 1132 is used to position the second attachment side142 against one side of two adjacent spinous processes. Because of thereduced profile of the securing means, such as the threaded member 451used in a worm gear securing means, the second attachment side 142 maybe more easily inserted from a lateral direction through ligamentsexisting between the two spinous processes (although, the device mayalso be inserted by removing all or a substantial portion of theligaments and inserted directly from the posterior direction). Thesecond attachment side 142 may further be seated by striking a flattenedsurface of the insertion instrument 1130 with a mallet or tamp. Thefirst attachment side is then attached to the securing means 1164 of thesecond arm 1134 of the insertion instrument 1130, and the second arm1134 is pivotally attached to the first arm 1132. The physician thensqueezes the handles of the insertion instrument 1130 to pivot the firstattachment side 140 in place against the opposite side of the same twospinous processes, inserting the spacer tray 150 through the ligamentsand aligning with its tray slot 210 on the second attachment side 142,while also operably aligning the securing means extending from thesecond attachment side 142 with the corresponding receiving member onthe first attachment side 140. In one embodiment, a punch instrument mayfirst be used prior to inserting either or both of the first and secondattachment sides, 140, 142 to remove a portion of the ligaments tofacilitate insertion and alignment of the attachment sides 140, 142. Thepunch instrument may operate in a manner similar to the insertioninstrument 1130, but include a punch (or may simply dilate) thatlaterally passes through and removes the ligaments when the handles aresqueezed together. The two attachment sides 140, 142 are pushed togetherenough to engage the securing means (e.g., worm screws meshing with theworm gearing, screws through a threaded collar, or shaft and gearmeshing with the gearing/rack, etc.). Then, to tighten the attachmentsides 140, 142 relative to each other, the operator can operate thesecuring means (e.g., turn the screw to operate the worm drivemechanism). Because of the ability of each attachment side 140, 142 topivot relative to the other, the interspinous process spacing device 130can be tightened against the spinous processes, irrespective of thepossible varied thicknesses of each spinous process. Once in a tightenedconfiguration, a set screw assembly may optionally be set to secure thesecond attachment end 142 to the spacer tray 150. It is appreciated thatother insertion instrument embodiments may be used to position andimplant an interspinous process spacing device, such as one in which asecuring means (e.g., gearing, worm gear, screw, ratchet, etc.) isintegrated as part of the insertion instrument, instead of, or inaddition to, being integrated with the interspinous process spacingdevice. Thus, in this embodiment, the tightening can at least partiallybe achieved by operating securing means of the insertion instrumentinstead of on the device to both tighten and loosen the insertioninstrument.

To implant a second (or subsequent) interspinous process spacing device132, the same steps are repeated with the exception of aligning theintegration means (e.g., fasteners, apertures, domes, pins, etc.) on theinner surfaces of the offset ends 149 (or a straight member) with theouter surfaces of the respective attachment ends of the adjacentinterspinous process spacing device 130.

Modifications and variations of the devices and methods described hereinwill be obvious to those skilled in the art from the foregoing detaileddescription. Such modifications and variations are intended to comewithin the scope of the appended claims and the example inventionsdescribed herein.

1. An interspinous process spacing device, comprising: a firstattachment side; a second attachment side; and a spacer extending fromthe first attachment side and slideably insertable through a spaceraperture formed in the second attachment side, the spacer adapted to bepositioned between a spinous process of a first vertebra and a spinousprocess of an adjacent second vertebra; wherein the first attachmentside and the second attachment side each comprise: a central portioncomprising: an anterior surface adapted to face anteriorly with respectto the first vertebra and the second vertebra; a posterior surfaceadapted to face posteriorly with respect to the first vertebra and thesecond vertebra; and an inner surface extending along at least amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the central portion; a first wing portionintegrally formed with and extending from the central portion, the firstwing portion comprising: an anterior surface adapted to face anteriorlywith respect to the first vertebra and the second vertebra; a posteriorsurface adapted to face posteriorly with respect to the first vertebraand the second vertebra; and an inner surface extending along at least amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the first wing portion; a second wingportion integrally formed with and extending from the central portion,the second wing portion comprising: an anterior surface adapted to faceanteriorly with respect to the first vertebra and the second vertebra; aposterior surface adapted to face posteriorly with respect to the firstvertebra and the second vertebra; and an inner surface extending alongat least a majority of an anterior-posterior height between the anteriorsurface and the posterior surface of the second wing portion; a firstbone fastener extending inwardly from the inner surface of the firstwing portion at a first fixed angle; and a second bone fastenerextending inwardly from the inner surface of the second wing portion ata second fixed angle; wherein the inner surface of the first wingportion extends in a direction transverse to the inner surface of thecentral portion; wherein the anterior-posterior height of the first wingportion is less than the anterior-posterior height of the centralportion; and wherein the inner surface of the first wing portion is notcoplanar with the inner surface of the second wing portion.
 2. Thedevice of claim 1, wherein the posterior surface of the first wingportion is coplanar with the posterior surface of the second wingportion.
 3. The device of claim 1, wherein the inner surface of thecentral portion and the inner surface of the first wing portion eachhave a planar shape, and wherein the inner surface of the first wingportion is angled relative to the inner surface of the central portionto define a predefined acute angle between the inner surface of thefirst wing portion and the inner surface of the central portion.
 4. Thedevice of claim 1, wherein the first attachment side and the secondattachment side each further comprise: a third bone fastener extendinginwardly from the inner surface of the first wing portion at a thirdfixed angle; and a fourth bone fastener extending inwardly from theinner surface of the second wing portion at a fourth fixed angle.
 5. Thedevice of claim 1, wherein a longitudinal axis of the first bonefastener extends at a non-perpendicular angle relative to the innersurface of the first wing portion.
 6. The device of claim 1, wherein thelongitudinal axis of the first bone fastener extends at a perpendicularangle relative to the inner surface of the central portion.
 7. Thedevice of claim 1, wherein a longitudinal axis of the second bonefastener extends at a perpendicular angle relative to the inner surfaceof the central portion.
 8. The device of claim 1, wherein the first wingportion further comprises a second inner surface extending along aminority of the anterior-posterior height of the first wing portion, andwherein the inner surface of the first wing portion extends in adirection transverse to the second inner surface of the first wingportion.
 9. The device of claim 8, wherein the inner surface and thesecond inner surface of the first wing portion each have a planar shape,and wherein the inner surface of the first wing portion is angledrelative to the second inner surface of the first wing portion to definea predefined acute angle between the inner surface of the first wingportion and the second inner surface of the first wing portion.
 10. Thedevice of claim 9, wherein the inner surface of the central portion hasa planar shape, and wherein the second inner surface of the first wingportion is coplanar with the inner surface of the central portion. 11.The device of claim 1, wherein the wherein the second wing portionfurther comprises a second inner surface extending along a minority ofthe anterior-posterior height of the second wing portion, and whereinthe inner surface of the second wing portion extends in a directiontransverse to the second inner surface of the first wing portion. 12.The device of claim 4, wherein a longitudinal axis of the third bonefastener extends at a perpendicular angle relative to the second innersurface of the first wing portion.
 13. The device of claim 4, wherein alongitudinal axis of the third bone fastener extends at a perpendicularangle relative to the inner surface of the central portion.
 14. Thedevice of claim 4, wherein a longitudinal axis of the third bonefastener extends parallel to a longitudinal axis of the first bonefastener.
 15. The device of claim 4, wherein a distal tip of the firstbone fastener and a distal tip of the third bone fastener are spacedapart from one another in a medial-lateral direction.
 16. The device ofclaim 1, wherein the first wing portion and the second wing portionextend in opposite directions from the central portion
 17. The device ofclaim 1, wherein the anterior-posterior height of the first wing portionis less than the anterior-posterior height of the second wing portion.18. The device of claim 1, further comprising securing means forsecuring the second attachment side relative to the first attachmentside.
 19. An interspinous process spacing device, comprising: a firstattachment side; a second attachment side; and a spacer extending fromthe first attachment side and slideably insertable through a spaceraperture formed in the second attachment side, the spacer adapted to bepositioned between a spinous process of a first vertebra and a spinousprocess of an adjacent second vertebra; wherein the first attachmentside and the second attachment side each comprise: a central portioncomprising: an anterior surface adapted to face anteriorly with respectto the first vertebra and the second vertebra; a posterior surfaceadapted to face posteriorly with respect to the first vertebra and thesecond vertebra; and an inner surface extending along at least amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the central portion; a first wing portionintegrally formed with and extending from the central portion, the firstwing portion comprising: an anterior surface adapted to face anteriorlywith respect to the first vertebra and the second vertebra; a posteriorsurface adapted to face posteriorly with respect to the first vertebraand the second vertebra; a first inner surface extending along amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the first wing portion; and a second innersurface extending along a minority of the anterior-posterior heightbetween the anterior surface and the posterior surface of the first wingportion; and a second wing portion integrally formed with and extendingfrom the central portion, the second wing portion comprising: ananterior surface adapted to face anteriorly with respect to the firstvertebra and the second vertebra; a posterior surface adapted to faceposteriorly with respect to the first vertebra and the second vertebra;and an inner surface extending along at least a majority of ananterior-posterior height between the anterior surface and the posteriorsurface of the second wing portion; wherein the first inner surface ofthe first wing portion extends in a direction transverse to each of theinner surface of the central portion and the second inner surface of thefirst wing portion; wherein the inner surface of the first wing portionis not coplanar with the inner surface of the second wing portion; andwherein the anterior-posterior height of the first wing portion is lessthan the anterior-posterior height of the central portion.
 20. Aninterspinous process spacing device, comprising: a first attachmentside; a second attachment side; and a spacer extending from the firstattachment side and slideably insertable through a spacer apertureformed in the second attachment side, the spacer adapted to bepositioned between a spinous process of a first vertebra and a spinousprocess of an adjacent second vertebra; wherein the first attachmentside and the second attachment side each comprise: a central portioncomprising: an anterior surface adapted to face anteriorly with respectto the first vertebra and the second vertebra; a posterior surfaceadapted to face posteriorly with respect to the first vertebra and thesecond vertebra; and an inner surface extending along at least amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the central portion; a first wing portionintegrally formed with and extending from the central portion, the firstwing portion comprising: an anterior surface adapted to face anteriorlywith respect to the first vertebra and the second vertebra; a posteriorsurface adapted to face posteriorly with respect to the first vertebraand the second vertebra; a first inner surface extending along amajority of an anterior-posterior height between the anterior surfaceand the posterior surface of the first wing portion; and a second innersurface extending along a minority of the anterior-posterior heightbetween the anterior surface and the posterior surface of the first wingportion; and a second wing portion integrally formed with and extendingfrom the central portion, the second wing portion comprising: ananterior surface adapted to face anteriorly with respect to the firstvertebra and the second vertebra; a posterior surface adapted to faceposteriorly with respect to the first vertebra and the second vertebra;and an inner surface extending along at least a majority of ananterior-posterior height between the anterior surface and the posteriorsurface of the second wing portion; a first bone fastener extendinginwardly from the first inner surface of the first wing portion at afirst fixed angle; a second bone fastener extending inwardly from theinner surface of the second wing portion at a second fixed angle; and athird bone fastener extending inwardly from the first inner surface ofthe first wing portion at a third fixed angle; wherein the first innersurface of the first wing portion extends in a direction transverse toeach of the inner surface of the central portion and the second innersurface of the first wing portion; wherein the anterior-posterior heightof the first wing portion is less than the anterior-posterior height ofthe central portion; and wherein a longitudinal axis of the first bonefastener extends parallel to a longitudinal axis of the third bonefastener.